Afghan plan must have "exit strategy": Obama

United States President Barack Obama said the U.S. must have an "exit strategy" in Afghanistan even as it expands its military, diplomatic and economic fight against a Taliban insurgency.

With violence rising ahead of elections in August, Obama has already committed an extra 17,000 troops to Afghanistan, but on Sunday he said military force alone would not end the war.

"What we can't do is think that just a military approach in Afghanistan is going to be able to solve our problems," he said in an interview with CBS' 60 Minutes.

"There's got to be an exit strategy," Obama said. "There's got to be a sense that this is not a perpetual drift."

Obama said his decision to send extra U.S. troops to Afghanistan was the most difficult he had to make since taking office.

Preventing al-Qaeda attacks

American commanders said as many as 30,000 additional troops are needed to overcome a stalemate in parts of Afghanistan. But some analysts caution against a gradual Vietnam-like escalation in a country historically hostile to outsiders.

In the CBS interview Obama narrowly defined the U.S. mission in Afghanistan as: "Making sure al-Qaeda cannot attack the U.S. homeland and U.S. interests and our allies. That's the number one priority."

"In service of that priority there may be a whole host of things that we need to do," he said. "We may need to build up economic capacity in Afghanistan. We may need to improve our diplomatic efforts in Pakistan."

"We may need to bring a more regional diplomatic approach to bear. We may need to coordinate more effectively with our allies. But we can't lose sight of what our central mission is," he said.

He said the mission was the same as when the United States went into Afghanistan after the Sept. 11, 2001 attacks, adding that projecting violence against U.S. citizens "is something that we cannot tolerate."

Making sure al-Qaeda cannot attack the U.S. homeland and U.S. interests and our allies. That's the number one priority

President Obama

The strategy is expected to rely on a major expansion of Afghanistan's own security forces, wooing "moderate" insurgents, stepping up civilian aid efforts and embarking on ambitious diplomacy across the region.

The outlines of the strategy have gradually emerged in public statements and media reports as Obama prepares to take his blueprint to a NATO summit in April, when he is expected to appeal to European allies for more help.

Citing Iraq as a possible model, Obama said he supports pursuing talks with elements of the Afghan insurgency, in hopes of isolating the hardline leadership allied with al-Qaeda.

The U.S. commander in Afghanistan, General David McKiernan, describes the war as a "stalemate."

Pakistan: key to the conflict

Even if all goes to plan inside Afghanistan, top officials say the key to the conflict lies across the border in Pakistan.

The Taliban and associated Islamists -- including al-Qaeda -- all operate from havens in Pakistan's northwest tribal areas and in the Swat Valley, despite repeated appeals to Islamabad from Washington.

Analysts say Washington is going to have to engage in dialogue with Taliban elements, a point Obama and Vice President Joe Biden have conceded recently, but in doing so will also have to juggle the competing interests of India and Pakistan.

"This is not going to work out smoothly," said C. Raja Mohan, Professor of South Asia Studies at Singapore's Nanyang Technology University. "Each step there are going to be complications."

India has been wary of any political accommodation with the Taliban, which were close allies of Pakistan before they were toppled by the U.S.-led invasion of Afghanistan in 2001.

Pakistan in turn has resented growing Indian influence in Afghanistan which it sees as an attempt by its much larger neighbor to put pressure on it from both east and west.