Assessing Threats to U.S. Vital Interests


Oct 30, 2019 19 min read

Military Index: Afghanistan/Pakistan
The Heritage Foundation

Terrorist threats from non-state actors in ungoverned areas of Afghanistan and Pakistan are an ongoing threat to the U.S. homeland, and the threat of regional war is exacerbated by nuclear rivalry and territorial disputes between Pakistan and India. One of the keys to America’s strategic footprint in Asia is its growing security partnership with India, which is geographically positioned between two major security threats: Pakistan to its west and China to its northeast. From Pakistan, India also faces the additional threat of terrorism, whether state-enabled or carried out without state knowledge or control.

Afghanistan War. On October 7, 2001, U.S. forces invaded Afghanistan in response to the September 11, 2001, terrorist attacks on the United States. This marked the beginning of Operation Enduring Freedom to combat al-Qaeda and its Taliban supporters. The U.S., in alliance with the United Kingdom and the anti-Taliban Afghan Northern Alliance forces, ousted the Taliban from power in December 2001. Most Taliban and al-Qaeda leaders fled across the border into Pakistan’s Federally Administered Tribal Areas, where they regrouped and started an insurgency in Afghanistan in 2003.

In August 2003, NATO joined the war in Afghanistan and assumed control of the International Security Assistance Force (ISAF). At the height of the war in 2011, there were 50 troop-contributing nations and nearly 150,000 NATO and U.S. forces on the ground in Afghanistan.

On December 28, 2014, NATO formally ended combat operations and relinquished responsibility to the Afghan security forces, which numbered around 352,000 (including army and police).1 After Afghan President Ashraf Ghani signed a bilateral security agreement with the U.S. and a Status of Forces Agreement with NATO, the international coalition launched Operation Resolute Support to train and support Afghan security forces.

In August 2017, while declining to announce specific troop levels, President Donald Trump recommitted America to the effort in Afghanistan and announced that “[c]onditions on the ground—not arbitrary timetables—will guide our strategy from now on.”2 According to the most recent available public information, the U.S. currently has around 14,000 troops in Afghanistan, split between the roughly 5,500 for the U.S.-led Operation Freedom Sentinel counterterrorism mission and slightly less than 8,500 for the NATO-led Resolute Support training mission. The latter also includes another approximately 8,500 troops from various NATO countries, bringing the total U.S. and NATO troop presence in Afghanistan to approximately 17,000.3 Most U.S. and NATO forces are stationed at bases in Kabul, with tactical advise-and-assist teams located there and in Mazar-i-Sharif, Herat, Kandahar, and Laghman.

In 2018, U.S. Special Envoy Zalmay Khalilzad began negotiations with the Taliban in Qatar in an attempt to find a political solution to the fighting. To date, little progress has been made. The Afghan government has not participated in the talks because the Taliban has refused to meet with them. This has caused tension between the U.S. and Afghan governments. Whether the U.S. will be able to bring all parties to the table and achieve a politically acceptable conclusion to the war remains to be seen. Meanwhile, U.S. forces in Afghanistan continue to face regular attacks from Taliban militants and their allies, although casualties have fallen considerably in recent years, with less than a dozen U.S. troops killed in combat in 2015, 2016, and 2017.4 There were 14 U.S. troop casualties in Afghanistan in 2018.5

In the spring of 2019, the Administration was rumored to be considering a plan to reduce American troop levels in Afghanistan by half while shifting the focus from counterterrorism to the training of Afghan security forces,6 but no final decision has been made.

Threats to the Homeland

Terrorist Groups Operating in Afghanistan and Pakistan (AfPak). Terrorist groups operating from Pakistan continue to pose a direct threat to the U.S. homeland. Pakistan is home to a host of terrorist groups that keep the region unstable and contribute to the spread of global terrorism. The killing of Osama bin Laden at his hideout in Abbottabad, Pakistan, in May 2011 and an intensive drone campaign in Pakistan’s tribal areas bordering Afghanistan have helped to degrade the al-Qaeda threat there, but the residual presence of al-Qaeda and the emergence of ISIS in neighboring Afghanistan remain serious concerns.

This is a deadly region. In December 2016, General John W. Nicholson, Jr., then-Commander, Resolute Support and U.S. Forces–Afghanistan, stated that “there are 98 U.S.-designated terrorist groups globally. Twenty of them are in the AfPak region. This represents the highest concentration of terrorist groups anywhere in the world…13 in Afghanistan, seven in Pakistan.”7

Efforts by ISIS to make inroads into Pakistan and Afghanistan have met with only limited success, most likely because of other terrorist groups’ well-established roots in the region. The Afghan Taliban views ISIS as a direct competitor for financial resources, recruits, and ideological influence. This competition was evident in a June 16, 2015, letter sent by the Taliban to ISIS leader Abu Bakr al-Baghdadi, urging his group not to take actions that could lead to “division of the Mujahideen’s command.”8 There also have been reports of clashes between ISIS militants and the Taliban in eastern and southern Afghanistan.

Reports of an ISIS presence in Afghanistan first began to surface in 2014, and the group has slowly gained a small foothold in the country. Though its actual numbers remain modest, its high-profile, high-casualty terrorist attacks have helped it to attract followers. In 2017 and 2018, several high-profile attacks in the Afghan capital and elsewhere targeted cultural centers, global charities, voter registration centers, and Afghan military and intelligence facilities, although they still pale in comparison to the number of attacks launched by the Taliban. In 2017 and 2018, ISIS representatives claimed responsibility for a series of attacks across Pakistan that killed over one hundred people and injured countless more.9

In April 2017, the U.S. military claimed that there were 700 ISIS fighters in Afghanistan; in November, however, General Nicholson said that 1,600 ISIS fighters had been “remov[ed]” from the battlefield since March.10 In June 2017, a U.S. air strike killed Abu Sayed, the head of ISIS-Khorasan. A report issued by the United Nations Security Council in February 2019 claimed that ISIS had “between 2,500 and 4,000” fighters in Afghanistan.11 U.S. estimates are roughly in agreement; the Lead Inspector General’s January 1, 2019–March 31, 2019, quarterly report on Operation Freedom’s Sentinel specifies 3,000–5,000.12 In March 2019, General Joseph Votel, the head of CENTCOM, said that he believed “ISIS Khorasan does have ideations focused on external operations toward our homeland.”13

Experts believe that there is little coordination between the ISIS-Khorasan branch operating in Afghanistan and the central command structure of the group located in the Middle East. Instead, it draws recruits from disaffected members of the Pakistani Taliban and other radicalized Afghans and has frequently found itself at odds with the Afghan Taliban, with which it competes for resources, territory, and recruits.

Pakistan’s continued support for terrorist groups that have links to al-Qaeda, the Taliban, and the Haqqani Network undermines U.S. counterterrorism goals in the region. Pakistan’s military and intelligence leaders maintain a short-term tactical approach of fighting some terrorist groups that are deemed to be a threat to the state while supporting others that are aligned with Pakistan’s goal of extending its influence and curbing India’s.

A December 16, 2014, terrorist attack on a school in Peshawar that killed over 150 people, most of whom were children, shocked the Pakistani public and prompted Prime Minister Nawaz Sharif’s government to introduce a National Action Plan (NAP) to reinvigorate the country’s fight against terrorism. Implementation of the NAP and the Pakistani military’s operations against TTP (Pakistani Taliban) hideouts in North Waziristan have helped to reduce Pakistan’s internal terrorist threat to some degree. According to the India-based South Asia Terrorism Portal, total fatalities in Pakistan (including terrorists/insurgents) have been on a steady decline since 2009, when they peaked at 11,704. Since then, they have fallen to 5,496 in 2014, 1,803 in 2016, 1,260 in 2017, 691 in 2018, and 228 as of June 23, 2019.14

However, there are few signs that Pakistan’s crackdown on terrorism extends to groups that target India, such as the Lashkar-e-Taiba (LeT), which was responsible for the 2008 Mumbai attacks, and the Jaish-e-Mohammed (JeM), which carried out an attack on the Indian parliament in 2001, another on the airbase at Pathankot in 2016, and the deadliest attack on Indian security forces in Kashmir in February 2019.15

Threat of Regional War

Pakistan’s Nuclear Weapons Stockpile. In September 2018, the Bulletin of the Atomic Scientists estimated that Pakistan “has a nuclear weapons stockpile of 140 to 150 warheads” that could “realistically grow to 220 to 250 warheads by 2025, if the current trend continues.”16 The possibility that terrorists could gain effective access to Pakistani nuclear weapons is contingent on a complex chain of circumstances. In terms of consequence, however, it is the most dangerous regional threat scenario. Concern about the safety and security of Pakistan’s nuclear weapons increases when India–Pakistan tensions increase. During the 1999 Kargil crisis, for example, U.S. intelligence indicated that Pakistan had made “nuclear preparations,” and this spurred greater U.S. diplomatic involvement in defusing the crisis.17

If Pakistan were to move around its nuclear assets or, worse, take steps to mate weapons with delivery systems, the likelihood of terrorist theft or infiltration would increase. Increased reliance on tactical nuclear weapons (TNWs) is of particular concern because launch authorities for TNWs are typically delegated to lower-tier field commanders far from the central authority in Islamabad. Another concern is the possibility that miscalculations could lead to regional nuclear war if India’s leaders were to lose confidence that nuclear weapons in Pakistan are under government control or, conversely, were to assume that they were under Pakistani government control after they ceased to be.

There are additional concerns that Islamist extremist groups with links to the Pakistan security establishment could exploit those links to gain access to nuclear weapons technology, facilities, and/or materials. The realization that Osama bin Laden stayed for six years within a half-mile of Pakistan’s premier defense academy has fueled concern that al-Qaeda can operate relatively freely in parts of Pakistan and might eventually gain access to Pakistan’s nuclear arsenal. The Nuclear Threat Initiative’s Nuclear Security Index ranks 22 countries with “weapons useable nuclear material” for their susceptibility to theft. Pakistan’s weapons-grade materials were ranked the 20th least secure in 2018, with only Iran’s and North Korea’s ranking lower.18

There is the additional (though less likely) scenario of extremists gaining access through a collapse of the state. While Pakistan remains unstable because of its weak economy, regular terrorist attacks, sectarian violence, civil–military tensions, and the growing influence of religious extremist groups, it is unlikely that the Pakistani state will collapse altogether. The country’s most powerful institution, the 550,000-strong army that has ruled Pakistan for almost half of its existence, would almost certainly intervene and assume control once again if the political situation began to unravel. The potential breakup of the Pakistani state would have to be preceded by the disintegration of the army, which currently is not plausible.19

Pakistan–India Conflict. India and Pakistan have fought four wars since partition in 1947, including conflicts in 1947, 1965, 1971, and 1999. Deadly border skirmishes across the Line of Control in Kashmir, a disputed territory claimed in full by both India and Pakistan, are commonplace.

Another India–Pakistan conflict would jeopardize multiple U.S. interests in the region and could increase the threat of global terrorism if Pakistan were destabilized. Pakistan would rely on militant non-state actors to help it fight India, thereby creating a more permissive environment in which various terrorist groups could operate freely. The potential for a nuclear conflict would threaten U.S. businesses in the region and disrupt investment and trade flows, mainly between the U.S. and India, whose bilateral trade in goods and services “totaled an estimated $142.1 billion in 2018.”20 A conflict would also strain America’s ties with one or both of the combatants at a time when Pakistan–U.S. ties are already under severe stress and America is trying to build a stronger partnership with India. The effects of an actual nuclear exchange—both the human lives lost and the long-term economic damage—would be devastating.

India and Pakistan are engaged in a nuclear competition that threatens stability throughout the subcontinent. Both countries tested nuclear weapons in 1998, establishing themselves as overtly nuclear weapons states, although India first conducted a “peaceful” nuclear weapons test in 1974. Both countries also are developing naval nuclear weapons and already possess ballistic missile and aircraft-delivery platforms.21

As noted, Pakistan has a stockpile of 140 to 150 nuclear warheads. It also “has lowered the threshold for nuclear weapons use by developing tactical nuclear weapons capabilities to counter perceived Indian conventional military threats.”22 This in turn affects India’s nuclear use threshold, which could affect China and possibly others.

The broader military and strategic dynamic between India and Pakistan has grown more volatile since the May 2014 election of Bharatiya Janata Party (BJP) leader Narendra Modi as India’s prime minister. Modi invited Pakistani Prime Minister Nawaz Sharif to his swearing-in ceremony but then later called off foreign secretary–level talks that were scheduled for August 2014 to express anger over a Pakistani official’s meeting with Kashmiri separatist leaders. During the same month, the two sides engaged in intense firing and shelling along their international border (called the working boundary) and across the Line of Control that divides Kashmir. A similar escalation in border tensions occurred again in October 2014 when a series of firing incidents claimed more than a dozen casualties with several dozen more injured.23

On December 25, 2015, a meeting did occur when Modi made an impromptu visit to Lahore—the first visit to Pakistan by an Indian leader in 12 years—to meet with Sharif. The visit created enormous goodwill between the two countries and raised hope that official dialogue would soon resume. Again, however, violence marred the new opening. Six days after the meeting, militants attacked an Indian airbase at Pathankot, killing seven Indian security personnel.24

As a result, official India–Pakistan dialogue remains deadlocked even though the two sides are reportedly communicating quietly through their foreign secretaries and national security advisers. With Prime Minister Modi’s BJP sweeping national elections in May 2019 and earning him a second term in office, few expect any major breakthroughs in the near term. As noted, Pakistan continues to harbor terrorist groups like Lashkar-e-Taiba and Jaish-e-Mohammed. The latter was responsible for a January 2, 2016, attack on the Indian airbase at Pathankot, a February 2018 attack on an Indian army camp in Kashmir, and a February 2019 attack on Indian security forces in Kashmir, the deadliest single terrorist attack in the disputed region since an insurgency erupted in 1989.25

Hafez Muhammed Saeed, LeT’s founder and the leader of its front organization Jamaat-ud-Dawa (JuD), has periodically been placed under arrest, only later to be released. Previously, he had operated freely in Pakistan, often holding press conferences and inciting violence against India during large public rallies.

Some observers remain concerned about the impact of an international troop drawdown in Afghanistan. Such a drawdown could enable the Taliban and other extremist groups to strengthen their grip in the region, further undermining stability in Kashmir and raising the chances of another major terrorist attack against India. A successful future attack on Indian interests in Afghanistan along the lines of the bombing of the Indian embassy in Kabul in 2008 would sharpen tensions between New Delhi and Islamabad.

With terrorist groups operating relatively freely in Pakistan and maintaining links to the country’s military and intelligence services, there is a moderate risk that the two countries might eventually engage in all-out conflict. Pakistan’s recent focus on incorporating tactical nuclear weapons into its warfighting doctrine has also raised concern that conflict now involves a higher risk of nuclear exchange.26

Pakistan’s nuclear weapons capability appears to have acted as a deterrent against Indian military escalation, both during the 2001–2002 military crisis and following the 2008 Mumbai attacks, but the Indian government has been under growing pressure to react strongly to terrorist provocations. In 2016, following an attack on an Indian army base in Uri, Kashmir, that killed 19 Indian soldiers, the Indian military reportedly launched surgical strikes on terrorist targets across the Line of Control in Pakistan-administered Kashmir. The Indian press indicated that up to 80 Indian commandos crossed the Line of Control on foot and destroyed seven “terror launch pads,” with attack helicopters on standby.27

Following a deadly attack on Indian security forces in Pulwama, Kashmir, in February 2019, India launched an even more daring cross-border raid. For the first time since the Third India–Pakistan War of 1971, the Indian air force crossed the Line of Control and dropped ordinance inside Pakistan proper (as opposed to disputed Kashmir), targeting several JeM training camps in Khyuber Pakhtunkhwa province.28 Delhi stressed that the “non-military” operation was designed to avoid civilian casualties and was preemptive in nature because it had credible intelligence that JeM was attempting other suicide attacks in the country.

In response, Pakistan launched fighter jets to conduct their own strike on targets located on India’s side of the Line of Control in Kashmir, prompting a dogfight that resulted in the downing of an Indian MiG-21. Whether there were any casualties on either side in either strike is unclear. Pakistan released the captured MiG-21 pilot days later, putting an end to the brief but dangerous crisis.


The threat to the American homeland emanating from the AfPak region is diverse, complex, and mostly indirect, largely involving non-state actors. The intentions of non-state terrorist groups like the TTP, al-Qaeda, and ISIS toward the U.S. are demonstrably hostile. In addition, despite the broad and deep U.S. relationships with Pakistan’s governing elites and military, it is likely that the political–military interplay in Pakistan and instability in Afghanistan will continue to result in an active threat to the American homeland.

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.

In addition, ongoing tensions between nuclear-armed rivals India and Pakistan could lead eventually to broader military conflict with some prospect of escalating to a nuclear exchange. Neither side desires another general war, and both countries have limited objectives and have demonstrated their intent to avoid escalation. However, the likelihood of miscalculation and escalation has grown considerably since 2016 when India ended its policy of not responding to Pakistani-backed terrorist attacks.

This Index assesses the overall threat from AfPak-based actors to the U.S. homeland as “testing” for level of provocation of behavior and “capable” for level of capability.

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  1. U.S. Department of Defense, Enhancing Security and Stability in Afghanistan, December 2016, p. 33, (accessed June 25, 2019).
  2. “Remarks by President Trump on the Strategy in Afghanistan and South Asia,” Fort Myer, Arlington, Virginia, August 21, 2017, (accessed June 25, 2019).
  3. North Atlantic Treaty Organization, Resolute Support Mission, “Resolute Support Mission (RSM): Key Facts and Figures,” February 2019, (accessed June 25, 2019). See also North Atlantic Treaty Organization, “NATO–Afghanistan Relations,” Media Backgrounder, February 2019, (accessed June 25, 2019).
  4. Nesar Azadzoi and Rod Nordland, “3 U.S. Soldiers Died in Afghanistan: Why This Fight Drags On,” The New York Times, November 27, 2018, (accessed May 28, 2019).
  5. Joanne Stocker, “US Service Members Killed in Afghanistan Operation,” The Defense Post, March 22, 2019, (accessed June 25, 2019).
  6. Thomas Gibbons-Neff and Julian E. Barnes, “Under Peace Plan, U.S. Military Would Exit Afghanistan Within Five Years,” The New York Times, February 28, 2019, (accessed May 28, 2019)
  7. Transcript, “Department of Defense Press Briefing by General Nicholson in the Pentagon Briefing Room,” U.S. Department of Defense, December 2, 2016, (accessed June 25, 2019). See also General John W. Nicholson, Commander, U.S. Forces–Afghanistan, statement on “The Situation in Afghanistan” before the Committee on Armed Services, U.S. Senate, February 9, 2017, p. 1, (accessed June 25, 2019).
  8. Sudarsan Raghavan, “Taliban in Afghanistan Tells Islamic State to Stay out of Country,” The Washington Post, June 16, 2016, (accessed June 25, 2019). See also Mirwais Harooni and Kay Johnson, “Taliban Urge Islamic State to ‘Interference’ in Afghanistan,” Reuters, June 16, 2015, (accessed June 25, 2019), and Aaron Y. Zelin, “Letter from the Taliban to Abu Bakr al-Baghdadi from the Head of the Shura Council,” Lawfare, June 27, 2015, (accessed June 25, 2019).
  9. Kunwar Khuldun Shahid, “Quetta Attack a Gory Reminder of Islamic State’s Presence in Balochistan,” The Diplomat, April 5, 2018. (accessed June 25, 2019).
  10. Transcript, “Department of Defense Press Briefing by General Nicholson via Teleconference from Kabul, Afghanistan,” U.S. Department of Defense, November 28, 2017, (accessed June 25, 2019).
  11. United Nations Security Council, Eighth Report of the Secretary-General on the Threat Posed by ISIL (Da’esh) to International Peace and Security and the Range of United Nations Efforts in Support of Member States in Countering the Threat, S/2019/103, February 1, 2019, p. 7, (accessed August 21, 2019).
  12. Office of Inspector General, U.S. Department of Defense; Office of Inspector General, U.S. Department of State; and Office of Inspector General, U.S. Agency for International Development, Operation Freedom’s Sentinel: Lead Inspector General Report to the United States Congress, January 1, 2019–March 31, 2019, p. 25, (accessed August 21, 2019).
  13. Eric Schmitt, Thomas Gibbons-Neff, Helene Cooper, and Alissa J. Rubin, “Its Territory May Be Gone, but the U.S. Fight Against ISIS Is Far from Over,” The New York Times, March 24, 2019, (accessed May 28, 2019).
  14. Institute for Conflict Management, South Asia Terrorism Portal, “Fatalities in Terrorist Violence in Pakistan 2000–2019,” data as of June 23, 2019, (accessed June 25, 2019).
  15. Ankit Panda, “Jaish-e-Mohammed Leader’s ‘Global Terrorist’ Designation Is Overdue,” The Diplomat, March 4, 2019, (accessed June 25, 2019).
  16. Hans M. Kristensen, Robert S. Norris, and Julia Diamond “Pakistani Nuclear Forces, 2018,” Bulletin of the Atomic Scientists, Vol. 74, Issue 5 (September 2018), pp. 346–358, (accessed June 25, 2019). See also Zeba Siddiqui, “Factbox: India and Pakistan–Nuclear Arsenals and Strategies,” Reuters, March 1, 2019, (accessed June 25, 2019).
  17. Peter R. Lavoy, ed., Asymmetric Warfare in South Asia: The Causes and Consequences of the Kargil Conflict (Cambridge, UK: Cambridge University Press, 2009), p. 10.
  18. Nuclear Threat Initiative, NTI Nuclear Security Index, Theft/Sabotage: Building a Framework for Assurance, Accountability, and Action, Fourth Edition, September 2018, (accessed June 25, 2019).
  19. Stephen P. Cohen, “The Future of Pakistan,” The Brookings Institution, South Asia Initiative, January 2011, p. 51, (accessed June 25, 2019).
  20. Executive Office of the President, Office of the United States Trade Representative, “India: U.S.–India Bilateral Trade and Investment,” last updated April 8, 2019, (accessed June 25, 2019).
  21. International Institute for Strategic Studies, The Military Balance 2018: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2018), p. 264 (India’s nuclear capabilities), and ibid., pp. 291 and 294 (Pakistan’s nuclear capabilities).
  22. Fact Sheet, “Nuclear Weapons: Who Has What at a Glance,” Arms Control Association, updated June 2018, (accessed June 25, 2019).
  23. Associated Press, “Worst Fighting in Years over Disputed Kashmir,” CBS News, October 9, 2014, (accessed June 25, 2019).
  24. Ralph Ellis, Euan McKirdy, and Harmeet Shah Singh, “Indian Prime Minister Urges Pakistan to Investigate Attack on Military Base,” CNN, updated January 5, 2016. (accessed June 25, 2019).
  25. Ravi Krishnan Khajuria, “Jammu Army Camp Attack: Two Soldiers Killed as JeM Militants Storm into Sunjuwan Base,” Hindustan Times, updated February 10, 2018, (accessed June 25, 2019), and BBC News, “Pulwama Attack: Nine Killed in Kashmir Gun Battle,” February 18, 2019, (accessed June 25, 2019).
  26. Ayaz Gul, “Pakistan Equips Military with Tactical Nuke-Capable Missile,” Voice of America, January 24, 2019, (accessed August 21, 2019).
  27. Sushant Singh, “Inside the Surgical Strike: Choppers on Standby, 70–80 Soldiers,” The Indian Express, updated October 1, 2016, (accessed June 25, 2019).
  28. Joanna Slater, “India Strikes Pakistan in Severe Escalation of Tensions Between Nuclear Rivals,” The Washington Post, February 26, 2019, (accessed June 25, 2019).