WASHINGTON -- John McCain said rival Barack Obama does not understand what's at stake in the Mideast a and the world and therefore chose to call for a withdrawal in Iraq based on political expediency and not conditions on the ground.

The presumptive Republican presidential nominee said he does not doubt Obama's patriotism, but he does question his actions in calling for a troop withdrawal in March 2007.

"If Senator Obama had had his way, we'd have been out last March and we'd been out in defeat and chaos, and probably had to come back again because of Iranian influence," McCain said in an interview on ABC's "This Week," taped at his home in Sedona, Ariz.

"He was wrong, I was right," McCain said, noting that he chose to support the surge of an additional 30,000 U.S. troops last spring that has now been widely credited with reducing violence in Iraq by 80 percent.

McCain said Obama made a decision on the surge based on whether it was the best way to appeal to the Democratic Party base.

"I am saying that he made the decision, which was political, in order to help him get the nomination of his party," he said.

Obama originally opposed the war in Iraq, which began in March 2003. He said he still does not support the surge, saying if his plan had been enacted to withdraw troops, conditions on the ground also would be very different right now.

Obama says if he is president he will initiate a withdrawal over the first 16 months of his administration. Visiting Iraq, Afghanistan, Israel, the Palestinian territories and three European nations, Obama said he was told by Iraqi leaders that nation does not want an open-ended presence of U.S. combat forces and now is an appropriate time to start planning for a reorganization of troops in Iraq. He also noted that the war costs about $10 billion a month, which could be used to shore up the U.S. economy.

McCain criticized that timeline even though he acknowledged Friday that that 16 months is "a pretty good timetable." However, he repeated Sunday that "anything is a good timetable" if it is based on conditions on the ground.

"I like six months, three months, two months.  I like yesterday.  I like yesterday, OK?  That seems really good to me.  But the fact is, the conditions on the ground have not dictated it," he said.

McCain said the Democratic presidential candidate does not understand the purpose of the surge or the war itself.

"He does not understand, and did not understand, and still doesn't understand that the surge was the vital strategy in us not having to lose a war.  Chaos, genocide, increased influence of Iranians in the region, the consequences of failure would have been severe, and now the benefits are enormous," McCain said.

"Saddam Hussein ... imposed a threat to the United States of America and our security.  And the Oil for Food scandal, the $12 billion he was skimming, the fact that he had said that he'd had in operation and he wanted to have weapons of mass destruction, the fact that this society that he ruled in such a brutal fashion was really awful, and he did pose a long-term threat to the security of the United States of America," he said.