In 2006, when the Democrats recaptured the House and Senate, there wasn’t any doubt about the antiwar mandate. That election was widely seen as a referendum on the Iraq War, and the new Democratic majority felt empowered by it. In 2008, though, it isn’t so clear. According to voter surveys and exit polls, the economy is now first and foremost on voters’ minds; and judging by Barack Obama’s first steps as president-elect, it’s the number-one thing on his mind, too.

There’s no question that for the vast majority of voters, Obama was seen as the antiwar candidate. Throughout the campaign, he said repeatedly, “I will end this war,” and he outlined an unconditional, sixteen-month timetable to withdraw US combat forces. According to exit polling, nearly two-thirds of those who voted disapproved of the war in Iraq, and those who strongly disapproved voted for Obama by a margin of eight to one.

Still, when the financial crisis exploded in September, Iraq receded as a front-burner issue. According to those same exit polls, only one voter in ten identified Iraq as their top concern. That could make it harder for Obama to claim that he has a mandate to end the war. But claim it he must, because as president-elect and then as president, he is going to face enormous pressure to abandon his pledge to withdraw.

That pressure will come from within his circle of advisers, some of whom saw Obama’s antiwar stance as good politics but bad policy. It will come from hawkish Democrats outside his circle and from those elbowing their way in, typified by Richard Holbrooke, who found himself shut out of Obamaland after he endorsed Hillary Clinton in the primaries. It may come from hawks close to Vice President-elect Joseph Biden, who voted for the Iraq War in 2002. It will certainly come from conservatives, neoconservatives and the editorial pages of the Washington Post and the Wall Street Journal. It will come from think tanks such as the Brookings Institution and the Center for a New American Security, which have close ties to Obama and the Democratic establishment.

Most of all, the pressure on Obama will come from the military, whose leadership won’t look kindly on an incoming administration that wants to change course. Indeed, a showdown with the military command could be the most dramatic event of Obama’s first weeks in office. It would pit him squarely against Adm. Mike Mullen, chairman of the Joint Chiefs of Staff; Gen. David Petraeus, the Centcom commander; and Gen. Ray Odierno, commander of US forces in Iraq, all of whom will argue strenuously against anything more than a limited withdrawal, tied to conditions on the ground.

Early in his administration, Obama may sit down with Petraeus–a politically savvy general who, it is rumored, is thinking about running for office himself, and who is the darling of the neoconservative movement–and tell him he intends to pull one to two combat brigades out of Iraq every month, starting immediately. And he’ll have to look around the room–at Mullen, Odierno, the Joint Chiefs and others, one by one. Each one of them will be aware of the pressure Obama will be under from hawks and right-wingers, and behind the scenes they’re likely to do what they can to fuel it. The Constitution gives Obama the power to order them to carry out the new policy, whether they like it or not. If they don’t, well, he can tell them not to let the door rattle their medals on the way out.

It may not be the equivalent of President Truman’s firing of Gen. Douglas MacArthur, but it’s possible Obama will have to clean house, putting in place generals prepared to accommodate the new commander in chief. There are many, typified by Gen. George Casey, the former US commander in Iraq, and Gen. John Abizaid, the former Centcom commander, who advocated a pullback in 2005-06 and who might be expected to go along with Obama’s policy. And in dealing with his generals, Obama can point out that the Iraqi government supports his timetable and that Baghdad is unwilling to sign a status-of-forces agreement that gives the United States a blank check to stay.

Yet there are worrying signs that Obama is feeling the pressure to climb down from his Iraq policy. During September and October, he made what appeared to be a tactical decision to stop touting his plan to end the occupation. It hardly came up during the Obama-McCain debates, although Obama did slam McCain for his poor judgment in supporting the war in 2003. Still, Obama did not aggressively put forward his withdrawal plan during the debates, and he was oddly defensive whenever McCain challenged him over the surge.

Equally troubling, Obama made it through the entire campaign refusing to say much about his plans for Iraq besides the withdrawal, including what a residual force might look like, i.e., how many troops might remain in Iraq after the withdrawal of combat brigades, and what their mission might be. (During the summer some Obama advisers wanted to draw a starker contrast with McCain over Iraq, and some wanted to muddy the differences. The mud advocates seem to have prevailed.)

Also worrisome is the support in the Obama camp for retaining President Bush’s defense secretary, Robert Gates, an idea that has won the backing of many in the Washington establishment. Gates is closely identified with the surge and, in tandem with Petraeus, he would probably counsel Obama to rethink the idea of unconditional withdrawal of combat forces. Also, by naming a Republican to Defense, Obama risks a concession to the canard that Democrats are ill-suited to handle national security, and he would pass up the opportunity to inject bold thinking and budget-cutting–both of which the Pentagon sorely needs.

Make no mistake: Iraq will be a difficult problem for Obama. Bush has handed him a country still perched on the brink of civil war, and it could flare up again at any moment. If violence grows, Obama may pay a political price, but get out he must. Doing so will require boldness, decisive action and skillful regional and international diplomacy. Obama’s cautious instincts may lead him to take the advice of those who urge him, instead, to go slow on Iraq. Continued popular mobilization against the war is needed to counter that pressure. Much is made of the 10 million e-mail addresses the Obama campaign put together over the past two years, and how President Obama can use that list to mobilize support for his policies. But e-mail works in both directions, and those 10 million Obama backers ought to start composing e-mails right now to deluge the White House over Iraq. The same goes for the organized peace and justice movement, which can’t afford to stand down.