The killing of Osama bin Laden was a hard-won victory for the United States. But the gains made that day, and in waging the war in Afghanistan - including putting al-Qaida on its heels - could be squandered if the Obama administration continues its plotted course.

When Republican presidential candidates lay out their foreign policy agendas in the Nov. 22 debate hosted by The Heritage Foundation and the American Enterprise Institute on CNN, they should pay significant attention to this seminal war. It's crucial to America's struggle against terrorism.

In June, President Obama announced his decision to bring home 10,000 troops by year's end and a total of 33,000 troops by next summer. This move happened despite requests from the Pentagon and Gen. David Petraeus to limit the initial withdrawal to 3,000 to 4,000.

That decision, as The Washington Post wrote, wasn't based in a "convincing military or strategic rationale." Rather, it was "at odds with the strategy adopted by NATO, which aims to turn over the war to the Afghan army by the end of 2014."

Apart from denying his military commanders the flexibility to determine the pace and scope of withdrawal based on conditions on the ground, the president "also risks upending the major achievement of eliminating Osama bin Laden across the border in Pakistan," Heritage's Lisa Curtis wrote at the time.

Curtis also noted that the decision would "further discourage Pakistan from cracking down on the Taliban leadership that finds sanctuary on its soil" and "reinforce Islamabad's calculation that the U.S. is losing resolve in the fight in Afghanistan and thus encourage Pakistani military leaders to continue to hedge on support to the Taliban to protect their own national security interests."

Unfortunately, after the president's decision, the United States reaped a bitter harvest sown by the Pakistani government. On Sept. 13, the U.S. Embassy in Kabul, Afghanistan, was attacked. Reports revealed that those responsible were linked to Pakistani intelligence officials.

Pakistan has hurt efforts

Then, in testimony before Congress, Adm. Mike Mullen, chairman of the U.S. Joint Chiefs of Staff, declared that Pakistan's military intelligence service is directing the Haqqani network, a militant group responsible for attacks on Americans, including the assault on the embassy.

Sadly, Pakistan's support of insurgent groups in Afghanistan is the most significant obstacle to achieving stability in the country. And the Pakistani military's refusal to take action against the Haqqani network seriously undermines U.S. and NATO success in the Afghan mission.

That mission is critical to the United States' continued prosecution of the war against terrorists. "Al-Qaida's core leadership remains in Pakistan's tribal areas bordering Afghanistan, and the Taliban (whose leadership is allied with al-Qaida) continues to threaten stability in Afghanistan," Heritage's James Carafano and Jessica Zuckerman point out.

There are steps that the U.S. should take to ensure success in Afghanistan, and they revolve around dealing with the main obstacle to progress: Pakistan.

First and foremost, the United States should reverse its withdrawal plan. It's important to show Pakistan that America isn't turning its back on the region and to ensure that no void is left for the Taliban to fill once again.

Next, since half of all supply routes to the NATO mission go through Pakistan, the U.S. should develop additional supply routes into Afghanistan. The United States should also freeze aid until Pakistan takes actions against perpetrators of the embassy attack and helps shut down the Haqqani network.

In addition, the United States should designate the Haqqani network a foreign terrorist organization, and establish a congressional commission to investigate Pakistan's role in fomenting the insurgency in Afghanistan. We need to determine the extent to which its actions are preventing the U.S. and NATO from achieving their security objectives in the region, and pursue an aggressive drone campaign against the Haqqani network.

There is much at stake in the war in Afghanistan. Americans have already made tremendous sacrifices. But their sacrifices shouldn't be rendered meaningless for the sake of scoring political victories at home.

The United States has made significant strides in the war against terrorism. But the president - and those who seek the White House - must realize that unless the U.S. changes course, America will slide backward in its mission to secure itself against those who would do us harm.

Mike Brownfield is in strategic communications at The Heritage Foundation.