Barack Obama has said there can be only one president at a time. But in this interregnum — when the White House has already given up on making foreign (or economic) policy — the words of the president-elect matter.

So how he describes the toughest security struggle he will face is important.

"I think it is a top priority for us to stamp out al-Qaida once and for all," Obama told "60 Minutes" recently. "And I think capturing or killing bin Laden is a critical aspect of stamping out al-Qaida. He is not just a symbol; he's also the operational leader of an organization that is planning attacks against U.S. targets."

This warning followed Obama's pledge in the Oct. 7 presidential debate: "We will kill bin Laden. We will crush al-Qaida. That has to be our biggest national-security priority."

But does it really make sense to focus our fight against Islamist militants on one man?

Obama's public pledge to get bin Laden may be a deliberate effort to prepare the American public for the shift of our military's focus from Iraq to Afghanistan. He has promised to send troops withdrawn from the former to the latter.

This shift in emphasis is correct: CIA director Michael Hayden said recently that al-Qaida remains the greatest threat to the United States, holed up in Pakistan's tribal areas along the Afghan border. "If there is a major strike on this country, it will bear the fingerprints of al-Qaida," he said.

The diversion of troops and intelligence assets to Iraq after our 2001 victory in Afghanistan permitted Taliban militants and al-Qaida to regroup in wild, Pashtun tribal areas across the border, from which they now attack NATO troops and threaten the stability of nuclear-armed Pakistan.

Getting bin Laden, Hayden said, would certainly have a "significant impact on the confidence of his followers." Yet Hayden also admitted that "we simply don't know what would happen if bin Laden is killed or captured."

Al-Qaida is a franchise organization in which young militants organize small cells around the world and then look to the home organization for guidance or training. But there's no guarantee that this militancy would end with bin Laden's death.

More to the point, we don't have much clue as to where he's hiding out.

Intelligence officials have not had a solid lead as to his whereabouts since late 2001. That's when U.S. commanders muffed the chance to capture him during the battle of Tora Bora.

To catch bin Laden, one of two things would have to happen, neither of them probable in the near term.

Either we need an incredibly lucky break in communications intercepts — unlikely, since the al-Qaida leader and his circle no longer use cell phones — or we need to acquire vastly better human intelligence in Pakistan's remote and mountainous tribal areas. But winning over those tribes is a job that can be done only by the Pakistani government and military. That would require closer U.S.-Pakistani cooperation.

We are talking long term. It may take years before we nab al-Qaida's No. 1, though we can hurt his organization badly in the meantime. Putting the public focus on catching bin Laden is setting ourselves up to fail.

As former ambassador to Afghanistan, Ronald Neumann, told me: "On the one hand, you may not achieve it, and on the other hand, it might not matter much. You are going to have to level with people about how long we'll be there and why we're there."

Indeed, one of Obama's most crucial tasks will be to lay out to the public our broad strategy and goals for Afghanistan and Pakistan.

The president-elect must explain why it's important to expand our military presence in Afghanistan — to prevent Afghanistan from becoming, once more, a terrorist haven. He also must explain how we'll avoid another military quagmire.

Obama needs to lay out why we need to aid the weak government and military of Pakistan, an ally that has failed to cooperate in the fight against Islamists in the past, but is doing so now. And he must be frank about the fact that the war on al-Qaida won't be a short war. It will require an effort to stabilize an entire region, involving diplomatic efforts that include Iran, Russia and China.

This plays to Obama's strengths and to the strengths of Gen. David Petraeus, whose command now extends from the Middle East to Pakistan. But it's much bigger than the effort to kill one man.

So let's drop the rhetoric about catching bin Laden and start preparing Americans for what this struggle really entails.


Trudy Rubin is a columnist and editorial-board member for the Philadelphia Inquirer. Reach her at trubin@phillynews.com.