Two wars. In Iraq, the U.S. is ramping down. In Afghanistan, the U.S. is ramping up.

Besides the 17,000 troops President Obama added in February, he will send 4,000 new troops and hundreds of civilian advisers to Afghanistan. "To focus on the greatest threat to our people, America must no longer deny resources to Afghanistan because of the war in Iraq," the president declared on March 27.

The war in Afghanistan has a clearer justification. Obama alluded to the comparison when he said, "The United States of America did not choose to fight a war in Afghanistan. Nearly 3,000 of our people were killed on September 11, 2001, for doing nothing more than going about their daily lives." Afghanistan also involves a more threatening enemy. "I want the American people to understand that we have a clear and focused goal: to disrupt, dismantle, and defeat Al Qaeda in Pakistan and Afghanistan," the president said.

Obama himself sounded a little Bushy when he said, "To the terrorists who oppose us, my message is the same: We will defeat you."

Nevertheless, the American public has been wary about the war in Afghanistan. Americans polled in February by CNN and Opinion Research were divided. Just under half said they supported the war in Afghanistan (47 percent); just over half said they opposed it (51 percent).

Opposition to U.S. involvement in Afghanistan is more muted than is opposition to the war in Iraq. Two-thirds of Americans oppose the Iraq war, a proportion that has held fairly steady for more than two years. But opposition to Afghanistan among Democrats is not so restrained: 64 percent of them oppose the war there.

Why are Americans wary about Afghanistan? For one thing, the recession. For another, Iraq war fatigue. Plus, the public is frustrated. Only 31 percent of Americans think that the United States is winning in Afghanistan. By comparison, 50 percent think that the U.S. is winning in Iraq, the highest number in at least five years. Nevertheless, Americans are eager to get U.S. troops out of Iraq.

When Obama announced he would send 17,000 more troops to Afghanistan, the public was willing to give the new president the benefit of the doubt. Sixty-three percent, including a majority of Democrats, supported the escalation. Democrats seem willing to go along with their leader, but they are less enthusiastic than Republicans: 77 percent of Republicans support escalation compared with 58 percent of Democrats.

Obama's biggest danger on the issue is opposition from his own party. The Vietnam and Iraq anti-war movements were formative political experiences for many Democrats. "I am deeply concerned," Rep. Lynn Woolsey, D-Calif., said on the House floor last month. "If we don't learn from our Iraq experience, we are doomed to repeat it."

On the other hand, Senate Minority Leader Mitch McConnell, R-Ky., congratulated Obama, saying, "A surge in Afghanistan is a good idea."

"The president has done a fairly significant pivot away from his roots in the left portion of the Democratic Party, and I think he should be commended for it," McConnell said. Democrats may have been startled to hear McConnell go on to say, "He came to the same kind of conclusion you would have expected from the Bush administration." Obama himself sounded a little Bushy when he said, "To the terrorists who oppose us, my message is the same: We will defeat you." Of course, terrorists, including Al Qaeda and its enablers in the Taliban, are seen as enemies by all Americans. Still, the White House has to worry that a protracted, inconclusive war in Afghanistan with mounting American casualties could become "Obama's War."

Americans believe that the U.S. can win a military victory in Afghanistan (62 percent in the CNN poll). The problem is that Afghanistan has become a political war. Winning depends not just on what the United States can do but also on what Afghanistan and Pakistan can do. Obama said, "Pakistan must demonstrate its commitment to rooting out Al Qaeda and the violent extremists within its borders." To succeed in Afghanistan, he said, "we and our friends must reverse the Taliban's gains and promote a more capable and accountable Afghan government." Americans express far less confidence in Afghanistan's and Pakistan's capabilities than in those of the United States.

This article appeared in the Saturday, April 4, 2009 edition of National Journal.

Want to stay ahead of the curve? Sign up for National Journal’s AM & PM Must Reads. News and analysis to ensure you don’t miss a thing.