The United States maintains a military force primarily to protect the homeland from attack and to protect its interests abroad. There are secondary uses—for example, to assist civil authorities in times of emergency or to deter enemies—but this force’s primary purpose is to make it possible for the U.S. to physically impose its will on an enemy when necessary.
It is therefore critical that the condition of the United States military with respect to America’s vital national security interests, threats to those interests, and the context within which the U.S. might have to use “hard power” be understood. Because such changes can have substantial implications for defense policies and investment, knowing how these three areas change over time is likewise important.
Each year, The Heritage Foundation’s Index of U.S. Military Strength employs a standardized, consistent set of criteria, accessible both to government officials and to the American public, to gauge the U.S. military’s ability to perform its missions in today’s world. The inaugural 2015 edition established a baseline assessment on which each annual edition builds, assessing the state of affairs for its respective year and measuring how key factors have changed during the preceding year.
The Index is not an assessment of what might be, although the trends that it captures may well imply both concerns and opportunities that can guide decisions that are germane to America’s security. Rather, the Index should be seen as a report card for how well or poorly conditions, countries, and the U.S. military have evolved during the assessed year. The past cannot be changed, but it can inform, just as the future cannot be predicted but can be shaped.
What the Index Assesses
The Index of U.S. Military Strength assesses the ease or difficulty of operating in key regions based on existing alliances, regional political stability, the presence of U. S. military forces, and the condition of key infrastructure. Threats are assessed based on the behavior and physical capabilities of actors that pose challenges to vital U.S. national interests. The condition of America’s military power is measured in terms of its capability or modernity, capacity for operations, and readiness to handle assigned missions successfully. This framework provides a single-source reference for policymakers and other Americans who seek to know whether our military power is up to the task of defending our national interests.
Any discussion of the aggregate capacity and breadth of the military power needed to protect U.S. security interests requires a clear understanding of precisely what interests must be defended. Three vital interests have been specified consistently and in various ways by a string of Administrations over the past few decades:
- Defense of the homeland;
- Successful conclusion of a major war that has the potential to destabilize a region of critical interest to the U.S.; and
- Preservation of freedom of movement within the global commons (the sea, air, outer-space, and cyberspace domains) through which the world conducts its business.
To defend these interests effectively on a global scale, the United States needs a military force of sufficient size, or what is known in the Pentagon as capacity. The many factors involved make determining how big the military should be a complex exercise, but successive Administrations, Congresses, and Department of Defense staffs have managed to arrive at a surprisingly consistent force-sizing rationale: an ability to handle two major conflicts simultaneously or in closely overlapping time frames.
At its root, the current National Defense Strategy (NDS) implies the same force requirement. Its emphasis on a return to long-term competition with major powers, explicitly naming Russia and China as primary competitors,1 reemphasizes the need for the United States to have:
- Sufficient military capacity to deter or win against large conventional powers in geographically distant regions,
- The ability to conduct sustained operations against lesser threats, and
- The ability to work with allies and maintain a U.S. presence in regions of key importance sufficient to deter behavior that threatens U.S. interests.
No matter how much America desires that the world be a simpler, less threatening place more inclined to beneficial economic interactions than violence-laden friction, the patterns of history show that competing powers consistently emerge and that the U.S. must be able to defend its interests in more than one region at a time. Consequently, this Index embraces the two-war or two-contingency requirement.
Since its founding, the U.S. has been involved in a major “hot” war every 15–20 years. Since World War II, the U.S. has also maintained substantial combat forces in Europe and several other regions while simultaneously fighting major wars as circumstances demanded. The size of the total force roughly approximated the two-contingency model, which has the inherent ability to meet multiple security obligations to which the U.S. has committed itself while also modernizing, training, educating, and maintaining the force. Accordingly, our assessment of the adequacy of today’s U.S. military is based on the ability of America’s armed forces to engage and defeat two major competitors at roughly the same time.
We acknowledge that absent a dramatic change in circumstances such as the onset of a major conflict, a multitude of competing interests that evolve during extended periods of peace and prosperity will cause Administrations and Congresses to favor spending on domestic programs rather than investing in defense. Consequently, garnering sufficient support to increase defense spending to the level needed for a force with a two-war capacity is problematic. But this political condition does not change the patterns of history, the behavior of competitors, or the reality of what it takes to defend America’s interests in an actual war.
This Index’s benchmark for a two-war force is derived from a review of the forces used for each major war that the U.S. has undertaken since World War II and the major defense studies completed by the federal government over the past 30 years. We concluded that a standing (Active component) two-war–capable Joint Force would consist of:
- Army: 50 brigade combat teams (BCTs);
- Navy: 400 battle force ships and 624 strike aircraft;
- Air Force: 1,200 fighter/ground-attack aircraft;
- Marine Corps: 30 battalions; and
- Space Force: metric not yet established.
This recommended force does not account for homeland defense missions that would accompany a period of major conflict and are generally handled by Reserve and National Guard forces. Nor does it constitute the totality of the Joint Force, which includes the array of supporting and combat-enabling functions that are essential to the conduct of any military operation: logistics; transportation (land, sea, and air); health services; communications and data handling; and force generation (recruiting, training, and education), to name only a few. Rather, these are combat forces that are the most recognizable elements of America’s hard power but that also can be viewed as surrogate measures for the size and capability of the larger Joint Force.
The Global Operating Environment
Looking at the world as an environment in which U.S. forces would operate to protect America’s interests, the Index focused on three regions—Europe, the Middle East, and Asia—because of the intersection of our vital interests and actors able to challenge them.
Europe. Overall, the European region remains a stable, mature, and friendly operating environment. Russia remains the preeminent military threat to the region, both conventionally and unconventionally, but the threat posed by Chinese propaganda, influence operations, and investments in key sectors is also significant and needs to be addressed. Both NATO and many European countries apart from those in the alliance have reason to be increasingly concerned about the behavior and ambitions of both countries, although agreement on a collective response to these challenges remains elusive.
America’s closest and oldest allies are located in Europe, and the region is incredibly important to the U.S. for economic, military, and political reasons. Perhaps most important, the U.S. has treaty obligations through NATO to defend the European members of that alliance. If the U.S. needs to act in the European region or nearby, there is a history of interoperability with allies and access to key logistical infrastructure that makes the operating environment in Europe more favorable than the environments in other regions in which U.S. forces might have to operate.
The past year saw continued U.S. reengagement with the continent, both militarily and politically, along with modest increases in European allies’ defense budgets and capability investments. Despite allies’ initial concerns, the U.S. has increased its investment in Europe, and its military position on the continent is stronger than it has been for some time.
The coronavirus caught the U.S. and Europe off-guard, led to disrupted or cancelled exercises, and caused Europe’s armed forces to take on new and unexpected roles in assisting with the response to the pandemic. The pandemic’s economic, political, and societal impacts are only beginning to be felt and will undoubtedly have to be reckoned with for years to come, in particular with respect to Europe’s relationship with China. NATO employed a host of resources in responding to the pandemic while continuing to ensure that the pandemic did not undermine the alliance’s collective defense.
NATO’s renewed emphasis on collective defense has resulted in a focus on logistics, newly established commands that reflect a changed geopolitical reality, and a robust set of exercises. NATO’s biggest challenges derive from capability and readiness gaps among many European nations, continuing improvements and exercises in the realm of logistics, a tempestuous Turkey, disparate threat perceptions within the alliance, and the need to establish the ability to mount a robust response to both linear and nonlinear forms of aggression.
For Europe, scores this year remained steady, as they did in 2019 (assessed in the 2020 Index), with no substantial changes in any individual categories or average scores. The 2021 Index again assesses the European Operating Environment as “favorable.”
The Middle East. For the foreseeable future, the Middle East region will remain a key focus for U.S. military planners. Once considered relatively stable, mainly because of the ironfisted rule of authoritarian regimes, the area is now highly unstable and a breeding ground for terrorism.
Overall, regional security has deteriorated in recent years. Even though the Islamic State (or at least its physical presence) appears to have been defeated, the nature of its successor is unclear. Iraq has restored its territorial integrity after the defeat of ISIS, but the political situation and future relations between Baghdad and the U.S. will remain difficult as long as a government that is sympathetic to Iran is in power. The regional dispute with Qatar has made U.S. relations in the region even more complex and difficult to manage, although it has not stopped the U.S. military from operating.
Many of the borders created after World War I are under significant stress. In countries like Iraq, Libya, Syria, and Yemen, the supremacy of the nation-state is being challenged by non-state actors that wield influence, power, and resources comparable to those of small states. The region’s principal security and political challenges are linked to the unrealized aspirations of the Arab Spring, surging transnational terrorism, and meddling by Iran, which seeks to extend its influence in the Islamic world. These challenges are made more difficult by the Arab–Israeli conflict, Sunni–Shia sectarian divides, the rise of Iran’s Islamist revolutionary nationalism, and the proliferation of Sunni Islamist revolutionary groups. COVID-19 will likely exacerbate these economic, political, and regional crises, which could destabilize the post-pandemic operational environment for U.S. forces.
Thanks to its decades of military operations in the Middle East, the U.S. has tried-and-tested procedures for operating in the region. Bases and infrastructure are well established, and the logistical processes for maintaining a large force forward deployed thousands of miles away from the homeland are well in place. Moreover, unlike in Europe, all of these processes have been tested recently in combat. The personal links between allied armed forces are also present. Joint training exercises improve interoperability, and U.S. military educational courses regularly attended by officers (and often royals) from the Middle East allow the U.S. to influence some of the region’s future leaders.
America’s relationships in the region are based pragmatically on shared security and economic concerns. As long as these issues remain relevant to both sides, the U.S. is likely to have an open door to operate in the Middle East when its national interests require that it do so.
Circumstances in all measured areas vary throughout the year, but in general terms, the 2021 Index assesses the Middle East Operating Environment as “moderate,” although the region’s political stability remains “unfavorable.”
Asia. The Asian strategic environment is extremely expansive, as it includes half the globe and is characterized by a variety of political relationships among states that have wildly varying capabilities. The region includes long-standing American allies with relationships dating back to the beginning of the Cold War as well as recently established states and some long-standing adversaries such as North Korea.
American conceptions of the region must recognize the physical limitations imposed by the tyranny of distance and the very real differences in relationships among regional powers that both make Asia so different from Europe and influence America’s relationships with both regions. Moving forces within the region (never mind to it) will take time and require extensive strategic lift assets as well as sufficient infrastructure, such as sea and aerial ports of debarkation that can handle American strategic lift assets, and political support. At the same time, because of the complicated nature of intra-Asian relations, especially unresolved historical and territorial issues of the type repeatedly exhibited in tensions between South Korea and Japan, the United States cannot necessarily count on support from all of its regional allies in responding to any given contingency, at least not in the opening days of a crisis.
Further, the lack of an integrated, regional security architecture along the lines of NATO means that there is no single standard to which all of the local militaries aspire, in addition to which most Asian militaries have limited combat experience, particularly in high-intensity air or naval combat. Although U.S. relations with countries such as the Philippines have been challenged by China’s aggressive outreach, especially on trade and infrastructure development projects, China’s increasingly aggressive posture (most recently demonstrated in its extension of security laws to Hong Kong) has caused countries to reconsider the risk of becoming too distant from the United States.
We continue to assess the Asian operating environment as “favorable” to U.S. interests in terms of alliances, overall political stability, militarily relevant infrastructure, and the presence of U.S. military forces.
Summarizing the condition of each region enables us to get a sense of how they compare in terms of the challenge the U.S. would have in projecting military power and sustaining combat operations in each one. As a whole, the global operating environment currently maintains a score of “favorable,” meaning that the United States should be able to project military power anywhere in the world as necessary to defend its interests without substantial opposition or high levels of risk.
Threats to U.S. Interests
Our selection of threat actors discounted troublesome states and non-state entities that lacked the physical ability to pose a meaningful threat to vital U.S. security interests. This reduced the population of all potential threats to a half-dozen that possessed the means to threaten U.S. vital interests and exhibited a pattern of provocative behavior that should draw the focus of U.S. defense planning. This Index characterizes their behavior and military capabilities on five-point, descending scales.
All of the six threat actors selected—Russia, China, Iran, North Korea, and terrorist groups in the Middle East and Afghanistan—remained actual or potential threats to U.S. interests over the past year. All amply demonstrated a commitment to expanding their capabilities to pursue their respective interests that directly challenged those of the U.S.
Compiling the assessments of threat sources, the 2021 Index again rates the overall global threat environment as “aggressive” and “gathering” in the areas of threat actor behavior and material ability to harm U.S. security interests, respectively, leading to an aggregated threat score of “high.”
Just as there are American interests that are not covered by this Index, there may be additional threats to American interests that are not identified here. The Index focuses on the more apparent sources of risk and those that appear to pose the greatest threat.
Russia remains the primary threat to American interests in Europe and is the most pressing threat to the United States. Moscow remains committed to massive pro-Russia propaganda campaigns in Ukraine and other Eastern European countries, has continued its active support of separatist forces in Ukraine, regularly performs provocative military exercises and training missions, and continues to sell and export arms to countries that are hostile to U.S. interests (its sale of the S-400 air defense system to Turkey being a prime example). It also has increased its investment in modernizing its military and has gained significant combat experience while continuing to sabotage U.S. and Western policy in Syria and Ukraine.
The 2021 Index again assesses the threat emanating from Russia as “aggressive” in its behavior and “formidable” (the highest category on the scale) in its growing capabilities.
China, the most comprehensive threat that the U.S. faces, continues to modernize and expand its military and pay particular attention to its space, cyber, and artificial intelligence capabilities. The People’s Liberation Army continues to extend its reach and military activity beyond its immediate region and engages in larger and more comprehensive exercises, including live-fire exercises in the East China Sea near Taiwan and aggressive naval and air patrols in the South China Sea. Its ongoing probes of the South Korean and Japanese air defense identification zones have drawn rebukes from both Seoul and Tokyo, and its statements about Taiwan and its exercise of military capabilities in the air and sea around the island have grown more belligerent.
The 2021 Index assesses the threat emanating from China as “aggressive” in the scope of its provocative behavior and “formidable” for its capability.
Iran represents by far the most significant security challenge to the United States, its allies, and its interests in the greater Middle East. Its open hostility to the United States and Israel, sponsorship of terrorist groups like Hezbollah, and history of threatening the commons underscore the problem it could pose. Today, Iran’s provocations are mostly a concern for the region and America’s allies, friends, and assets there. Iran relies heavily on irregular (to include political) warfare against others in the region and fields more ballistic missiles than any of its neighbors. The development of its ballistic missiles and potential nuclear capability also mean that it poses a long-term threat to the security of the U.S. homeland. Iran has also continued its aggressive efforts to shape the domestic political landscape in Iraq, adding to the general instability of the region.
The 2021 Index extends the 2020 Index assessment of Iran’s behavior as “aggressive” and its capability as “gathering.”
North Korea’s military poses a security challenge for American allies South Korea and Japan, as well as for U.S. bases in those countries and Guam. North Korean officials are belligerent toward the United States, often issuing military and diplomatic threats. Pyongyang also has engaged in a range of provocative behavior that includes nuclear and missile tests and tactical-level attacks on South Korea.
North Korea has used its missile and nuclear tests to enhance its prestige and importance domestically, regionally, and globally and to extract various concessions from the United States in negotiations over its nuclear program and various aid packages. Such developments also improve North Korea’s military posture. U.S. and allied intelligence agencies assess that Pyongyang has already achieved nuclear warhead miniaturization, the ability to place nuclear weapons on its medium-range missiles, and an ability to reach the continental United States with a missile.
This Index therefore assesses the overall threat from North Korea, considering the range of contingencies, as “testing” for level of provocation of behavior and “gathering” for level of capability.
In the Afghanistan–Pakistan (AfPak) region, non-state terrorist groups pose the greatest threat to the U.S. homeland and the overall stability of the South/Southwest Asia region. Pakistan represents a paradox: It is both a security partner and a security challenge. Islamabad provides a home and support to terrorist groups that are hostile to the U.S., to other U.S. partners in South Asia like India, and to the government in Afghanistan, which is particularly vulnerable to destabilization efforts. Both Pakistan and Afghanistan are already among the world’s most unstable states, and the instability of the former, given its nuclear arsenal, has a direct bearing on U.S. security. Afghanistan’s inability to control many parts of the country and Pakistan’s willingness to host and support terrorist groups provide opportunity to entities such as al-Qaeda, the Haqqani Network, the Taliban, and affiliates of the Islamic State to operate.
This Index therefore assesses the overall threat from AfPak-based actors to the U.S. and its interests as “testing” for level of provocation of behavior and “capable” for level of capability.
A broad array of terrorist groups remain the most hostile of any of the threats to America examined in the Index. The primary terrorist groups of concern to the U.S. homeland and to Americans abroad are the Islamic State of Iraq and al-Sham (ISIS) and al-Qaeda. Al-Qaeda and its branches remain active and effective in Syria, Yemen, Iraq, and the Sahel of northern Africa. Thought no longer to be a territory-holding entity, ISIS also remains a serious presence in the Middle East, in South and Southeast Asia, and throughout Africa, posing threats to stability as it seeks to overthrow governments and impose an extreme form of Islamic law. Its ideology continues to inspire attacks against Americans and U.S. interests. Fortunately, Middle East terrorist groups remain the least capable threats facing the U.S., but they cannot be dismissed.
Our combined score for threats to U.S. vital interests is “high,” the fourth on a five-level scale, just below “severe.”
The Status of U.S. Military Power
Finally, we assessed the military power of the United States in three areas: capability, capacity, and readiness. We approached this assessment by military service as the clearest way to link military force size; modernization programs; unit readiness; and (in general terms) the functional combat power (land, sea, and air) represented by each service.
We treated the United States’ nuclear capability as a separate entity because of its truly unique characteristics and constituent elements, from the weapons themselves to the supporting infrastructure that is fundamentally different from the infrastructure that supports conventional capabilities. And while not fully assessing cyber and space as we do the Army, Navy, Air Force, and Marine Corps, we also acknowledge the importance of these new tools and organizations that have become essential to deterring hostile behavior and winning wars.
These three areas of assessment (capability, capacity, and readiness) are central to the overarching questions of whether the U.S. has a sufficient quantity of appropriately modern military power and whether military units are able to conduct military operations on demand and effectively.
As reported in all previous editions of the Index, the common theme across the services and the U.S. nuclear enterprise is one of force degradation and the effort needed to rebuild after such degradation, which has been caused by many years of underinvestment, poor execution of modernization programs, and the negative effects of budget sequestration (cuts in funding) on readiness and capacity in spite of repeated efforts by Congress to provide relief from low budget ceilings imposed by the Budget Control Act of 2011. Pursuant to new guidance provided by then-Secretary of Defense James Mattis in the 2018 NDS, the services undertook efforts to reorient from irregular warfare to large-scale combat against a peer adversary, but such shifts take time and even more resources.
While the military has been heavily engaged in operations, primarily in the Middle East but elsewhere as well, since September 11, 2001, experience in warfare is both ephemeral and context-sensitive. Valuable combat experience is lost as the servicemembers who individually gained experience leave the force, and it retains direct relevance only for future operations of a similar type: Counterinsurgency operations in Iraq, for example, are fundamentally different from major conventional operations against a state like Iran or China. The withdrawal of U.S. military forces from Iraq, in general, in 2011 (now nearly a decade in the past) and the steady reduction of forces in Afghanistan have amplified the loss of direct combat experience across the Joint Force. Thus, although portions of the current Joint Force are experienced in some types of operations, the force as a whole lacks experience with high-end, major combat operations toward which it has only recently begun to redirect its training and planning, and it is still aged and shrinking in its capacity for operations even if limited quantities of new equipment like the F-35 Lightning II fighter are gradually being introduced.
We characterized the services and the nuclear enterprise on a five-category scale ranging from “very weak” to “very strong,” benchmarked against criteria elaborated in the full report. These characterizations should not be construed as reflecting either the competence of individual servicemembers or the professionalism of the services or Joint Force as a whole; nor do they speak to the U.S. military’s strength relative to other militaries around the world. Rather, they are assessments of the institutional, programmatic, and material health or viability of America’s hard military power.
Our analysis concluded with these assessments:
- Army as “Marginal.” The Army’s score remains “marginal” in the 2021 Index. The Army has fully committed to modernizing its forces for great-power competition, but its programs are still in their development phase, and it will be a few years before they are ready for acquisition and fielding. It remains “weak” in capacity with 70 percent of the force it should have but has significantly increased the readiness of the force, scoring the highest level of “very strong” in 2020. The Army has a better sense of what it needs for war against a peer, but funding uncertainties could threaten its ability to realize its goals.
- Navy as “Marginal,” Trending Toward “Weak.” The Navy’s overall score remains “marginal” in the 2021 Index but is trending toward “weak” in capability and readiness and remains “weak” in capacity. The technology gap between the Navy and its peer competitors is narrowing in favor of competitors, and the Navy’s ships are aging faster than they are being replaced. The Navy sustained its focus on improving readiness in 2020, but it has a very large hole to fill, its fleet is too small relative to workload, and supporting shipyards are overwhelmed by the amount of repair work needed to make more ships available.
- Air Force as “Marginal.” The USAF scores “marginal” in all three measures but is trending upward in capability and capacity. The shortage of pilots and flying time for those pilots degrades the ability of the Air Force to generate the amount and quality of combat air power that would be needed to meet wartime requirements. Although it could eventually win a single major regional contingency (MRC), the time needed to win that battle and the attendant rates of attrition would be much higher than they would be if the service had moved aggressively to increase high-end training and acquire the fifth-generation weapon systems required to dominate such a fight.
- Marine Corps as “Marginal.” The score for the Corps’ capacity was raised to “marginal” from “weak” but only because this Index has changed the threshold, lowering it from 36 infantry battalions to 30 battalions in acknowledgement of the Corps’ argument that it is a one-war force that also stands ready for a broad range of smaller crisis-response tasks. However, the Corps intends to reduce its number of battalions further from 24 to 21, which would return it to a score of “weak.” The service is moving ahead aggressively with a redesign of its operating forces, but it continues to be hampered by old equipment, and problematic funding continues to constrain its deployment-to-dwell ratio to 1:2 (too few units for its workload), forcing it to prioritize readiness for deployed and next-to-deploy units at the expense of other units across the force.
- Space Force as “Not Assessed.” The Space Force was formally established on December 20, 2019, as a result of an earlier proposal by President Trump and legislation passed by the Congress.2 As of mid-2020, the Space Force is still in the process of being established. Personnel numbers are small. Given the nascent state of the Space Force, we do not render an assessment of the service in the 2021 Index. We hope to assess the strength of the service in future editions, but this will be complicated by the classified nature of the service.
- Nuclear Capabilities as “Marginal,” Trending Toward “Strong.” It should be emphasized that “trending toward strong” assumes that the U.S. maintains its commitment to modernization of the entire nuclear enterprise—from warheads to platforms to personnel to infrastructure—and allocates needed resources accordingly. Without this commitment, this overall score will degrade rapidly to “weak.” Continued attention to this mission is therefore critical. Although a bipartisan commitment has led to continued progress on U.S. nuclear forces modernization and warhead sustainment, these programs remain seriously threatened by potential future fiscal uncertainties. The infrastructure that supports nuclear programs is very aged, and nuclear test readiness has revealed troubling problems within the forces.
In the aggregate, the United States’ military posture is rated “marginal” and features both positive and negative trends: progress in bringing some new equipment into the force, filling gaps in manpower, and rebuilding stocks of munitions and repair parts alongside worrisome trends in force readiness, declining strength in key areas like trained pilots, and continued uncertainty across the defense budget. The 2021 Index concludes that the current U.S. military force is likely capable of meeting the demands of a single major regional conflict while also attending to various presence and engagement activities but that it would be very hard-pressed to do more and certainly would be ill-equipped to handle two nearly simultaneous MRCs, a situation made more difficult by the generally weak condition of key military allies.
The military services have prioritized readiness and have seen improvement over the past couple of years, but modernization programs continue to suffer as resources are redirected toward current operations, sustainment of readiness levels, and heavy investment in research and development programs to prepare the force for potential use 10 or 20 years in the future. The services have also normalized reductions in the size and number of military units, and the forces remain well below the level needed to meet the two-MRC benchmark.
Congress and the Administration took positive steps to stabilize funding for fiscal years 2018, 2019, and 2020 through the Bipartisan Budget Agreement of 2018, and the Bipartisan Budget Act of 2019 sustained support for funding above the caps imposed by the Budget Control Act of 2011 (BCA). While this allayed the most serious concerns about a return to the damaging levels of the BCA, more will be needed in the years to come to ensure that America’s armed services are properly sized, equipped, trained, and ready to meet the missions they are called upon to fulfill.
As currently postured, the U.S. military is only marginally able to meet the demands of defending America’s vital national interests.
- James Mattis, Secretary of Defense, Summary of the 2018 National Defense Strategy of the United States of America: Sharpening the American Military’s Competitive Edge, p. 2. https://dod.defense.gov/Portals/1/Documents/pubs/2018-National-Defense-Strategy-Summary.pdf (accessed August 12, 2020).
- See “Text of Space Policy Directive-4 (SPD-4), Establishment of the United States Space Force,” The White House, February 19, 2019, https://www.whitehouse.gov/presidential-actions/text-space-policy-directive-4-establishment-united-states-space-force/ (accessed August 12, 2020), and S. 1790, National Defense Authorization Act for Fiscal Year 2020, Public Law 116-92, 116th Cong., December 20, 2019, Title IX, Subtitle D, https://www.congress.gov/bill/116th-congress/senate-bill/1790 (accessed August 12, 2020). President Trump’s February 2019 directive established the Space Force as part of the Department of the Air Force (DOAF). The FY 2020 NDAA established the force as the fifth uniformed service within the Department of Defense and the second service within the DOAF. The service will reside under the direction and leadership of the Secretary of the Air Force. The NDAA specifies that a four-star general will serve as Chief of Space Operations (CSO) and a full member of the Joint Chiefs of Staff.