As predicted, Barack Obama's advocacy of unilateral military intervention in Pakistan if there is "actionable intelligence" against al-Qaeda is giving legitimacy to the Bush administration's gathering plan for an escalation.Obama's position is a revival of John Kerry's 2004 argument that the U.S. should have pursued Osama bin Ladin into Tora Bora but instead was distracted by the war in Iraq.The position balances Obama's dovishness on Iraq, making him more credible to the national security establishment. If a U.S. missile or counter-terrorism strike happens to kill bin Ladin, Obama can share credit. But the dangers are extremely high, requiring caution and pragmatism from a potential president. The American target in South Waziristan, Baitullah Mehsud, is categorized vaguely as an "al Qaeda associate" by U.S. officials. More deeply, he is an authentic leader of the Mehsud tribe, and an attack on him would further inflame Pashtun nationalism against the U.S. There is no evidence that Mehsud ordered the assassination of Benezir Bhutto, as the Musharraf regime initially suggested. Nor is it clear how the mujahadeen in South Waziristan pose a direct threat of another 9/11 attack against the U.S. What is absolutely clear is that the U.S. and NATO have failed to militarily defeat the Pashtun-based Taliban in Afghanistan, and any new American intervention in Pakistan will mobilize millions of Muslims against both the Musharraf dictatorship and its American backers. That means a three-front military quagmire in Iraq, Afghanistan and Pakistan, with no known resources to contain Iran -- which represents strategic drift on a grand scale.Fortunately, Obama's position contains a loophole, the requirement that there be "actionable intelligence," which can allow him to back away from a commitment to an escalated and probably futile war.At the moment, Obama is responsible for creating a bipartisan climate of support for a military intervention in a period of panic after the assassination of Benazir Bhutto. He can de-escalate the rush to war by calling for immediate hearings into the crisis in Pakistan, including independent voices from that country who fervently oppose the deepening secret war by the U.S. The hearings should probe the dangers of a Pakistani backlash against the U.S plan, the nature of the alleged enemy, and the costs and benefits of an expanded war.It would be a tragic irony if Obama supported Bush's failed policies and backed a new pre-emptive war against a sovereign country. The real question is whether the Bush policies have destabilized Pakistan fatally and presented anti-American elements a new opportunity to bleed American troops, overextend our military capacity, drain the American treasury, and further isolate America as a rogue state in the eyes of most countries in the world.With whatever finesse is required, Barack needs to back off. There is no more reason to rush to war in Pakistan on the basis of uncertain evidence than there was in Iraq in 2002.