The devastating terrorist attack on the Indian Embassy in Kabul last week signals a new sense of urgency to the Obama administration's deliberations over Gen. Stanley McChrystal's assessment of the war in Afghanistan.

Here's what Washington needs to understand: The road to stability in Afghanistan runs through Islamabad and New Delhi.

To diminish the mistrust and hostility that destabilizes Pakistan, India, and Afghanistan, the US needs to take a holistic regional approach.

Most important, the president should commit the United States to a gradual troop surge.

The leaked McChrystal report has been criticized for omitting an exit strategy, but what unnerves skeptical lawmakers reassures American allies in the region.

A surge will send a strong political message and prevent hedging by ordinary Afghans – not to mention the Pakistani and Indian security establishment – who are trying to gauge American resolve. As Kurt Volker, former US permanent representative to NATO, said: "If they think that the United States is packing up, they won't bet their lives on opposing extremists."

A phased troop buildup will signal our long-term commitment to stability in the region. With such assurances, Pakistan's security sector will be empowered to act more boldly in purging extremist elements from their midst.

Pakistani commentators rightly point out that much of the conflict across the border is fueled by disgust with the Afghan government, rebellion against foreign occupation, extreme Pashtun nationalism, and tribal dynamics. But they are reluctant to confront the reality that havens in their own country provide Taliban fighters with weapons, training, and the protection of Pakistan's intelligence service.

The US must focus on pressuring Pakistan to shut down these havens. Even the most dangerous elements of Pakistan's government will be more circumspect when they realize that the 60,000 plus US troops in their backyard aren't going anywhere.

We cannot stabilize Afghanistan without addressing the insecurities of the Pakistani military elite. That said, a harder line on Pakistan will only be effective if it is accompanied by reciprocal pressure on India.

Recent efforts to pilot a nonproliferation resolution in the UN Security Council might have ruffled feathers in New Delhi, but they calmed the generals in Islamabad. The administration should take the extra step of insisting that the US military contractors looking to cash in on the $100 billion modernization of the Indian military pack up and come home. Massive sales of US military technology to India could upset the region's fragile balance of power.

For years, Pakistan has asked Afghanistan to accept the Durand Line as the border between the two countries. Afghan ambiguity on the issue has bred Pakistani contempt. The US can use its leverage in Kabul to push the Afghan and Pakistani governments to jointly establish and secure their border.

These monumental diplomatic tasks can only be accomplished within the framework of formalized negotiations. It is notoriously difficult to get Indian, Afghan, and Pakistani decision makers in the same room, let alone to mediate their profound and existential grievances. The US has been hesitant to take on this challenge in the past, but a sustained troop presence in the region will give these negotiations a sense of permanence that previous appeals lacked.

In order to lay the framework for an official summit between the leaders of the three countries, the US should empower Special Representative Richard Holbrooke by expanding his mandate to encompass India. All concerns should be open for discussion, including Pakistani support of jihadi groups in Kashmir and alleged Indian and Afghan cooperation in arming Baloch separatists in Pakistan. Everyone at the table must agree to swallow a bitter pill.

American public support for the war is lagging. Americans are justly dismayed by the prospect that more blood and treasure will be spent to prop up a government that won an election through deceit and coercion. Afghan President Hamid Karzai's image has been permanently tarnished. But Afghanistan is bigger than one man.

Now more than ever it is essential for President Obama to stand with Afghanistan. If Democratic support is not forthcoming, he should court congressional Republicans.

American credibility and regional stability are at stake.

Joshua Gross is a master's candidate at the FletcherSchool of Law and Diplomacy at TuftsUniversity. He formerly served as the director of media relations for the Embassy of Afghanistan in Washington, and as a consultant for the Project on National Security Reform.

(Edited for space)