It's hard to keep up with Barack Obama's positions on the Iraq war. When he entered the presidential race, he offered a plan that would take more than a year to withdraw from Iraq. In September, he said he would withdraw all our combat brigades over 15 months or so. This week, he vowed to pull those forces out within 16 months of taking office.

Wow. He's really been all over the lot, hasn't he? No one can possibly tell if President Obama will get us out in February of 2010, or if he'll put it off till April.

Small wonder that a John McCain spokesman said that on Iraq, Obama "has held almost every conceivable position." Or that a blogger for the conservative American Spectator said Obama "has entered John Kerry territory when it comes to changing positions on Iraq."

See for yourself. Obama was against the war before it began — and then, in a complete reversal, he was against it after it began. When he launched his campaign in early 2007, he favored a phased withdrawal. But now, with the Democratic nomination in hand, what does he favor? A phased withdrawal.

Recently he said once in office, he would consult the military and "refine" his policies, while stressing his intention to get our troops out within — you will never guess — 16 months.

OK, maybe he's not so inconsistent. Waiting for Obama to alter his policy on Iraq has been like waiting for the Sphinx to smile.

It would be more believable for Republicans to blast him for being rigidly committed to withdrawal no matter what. There are two reasons they are not crazy about this option.

The first is that it would remind the electorate that Obama has always opposed a war that most Americans think was a mistake — and that he favors a near-term withdrawal, as most of them do and McCain does not.

The second is that his opponents want to paint him as a shameless flip-flopper. They would like to change the subject from whether the war was wise to whether Obama is a vertebrate. This tactic worked against the 2004 Democratic nominee, who famously said of a bill to fund the war, "I actually did vote for the $87 billion before I voted against it."

The problem they face is that Obama is no John Kerry. The Massachusetts senator voted for the resolution authorizing the war and later changed his mind about Iraq. This year's nominee was against the war from the beginning and in the subsequent six years has proven unwilling to reverse field.

Obama, however, has never called for an immediate exit, as some on the left would prefer. He has been consistent in refusing either to accelerate his schedule or to slow it down. I suspect when he talks in his sleep, he mumbles his mantra that "we have to be as careful getting out of Iraq as we were careless getting in."

His charge this week that the war in Iraq has diverted us from defeating the Taliban in Afghanistan and going after al-Qaida also sounds a bit familiar. He was criticized during the primaries for saying that if the opportunity arose to hit bin Laden in Pakistan, he would do it. A year ago, he gave a speech called, "The War We Need to Win," which called for "getting off the wrong battlefield in Iraq, and taking the fight to the terrorists in Afghanistan and Pakistan."

He was right then, and he's right now. Our recent progress in Iraq has come at a high price: growing violence and turmoil in Afghanistan, with the American death toll last month rising to the highest level since 2001.

McCain insists success in Iraq breeds success in Afghanistan. But Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, gives a different picture: "I don't have troops I can reach for, brigades I can reach, to send into Afghanistan until I have a reduced requirement in Iraq." The war in Iraq has drained resources needed to go after the people responsible for the Sept. 11 attacks, and the consequences are only getting worse.

That's one of the arguments Obama has been making for several years now. For all their charges of flip-flopping, Republicans aren't afraid he will cave on Iraq and Afghanistan. They're afraid he won't.

Steve Chapman blogs daily at newsblogs.chicagotribune.com/steve_chapman. To find out more about Steve Chapman, and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

COPYRIGHT 2008 CREATORS SYNDICATE, INC.