LAS VEGAS — Republican John McCain yesterday issued a scathing critique of Barack Obama's judgment and readiness to be commander in chief, telling a veterans' group his Democratic rival had tried to "legislate failure" in Iraq and placed his own ambition ahead of military success there.

Addressing the Disabled American Veterans convention here, McCain mocked what he called Obama's varying positions on the Bush administration's decision to send an additional 30,000 troops to Iraq last year. The GOP hopeful supported the so-called "surge" strategy, even as polls showed most voters opposed sending more troops into combat at the time.

Obama spoke out against the original invasion as an Illinois state senator and strongly opposed the subsequent troop increase in the U.S. Senate and on the campaign trail.

Since then, the surge has been credited with helping stabilize Iraq and reduce violence there. Obama has argued that it has not brought about the political reconciliation needed to create lasting peace in the country.

But in a tacit acknowledgment that his assessment of the troop increase may have proven incorrect, Obama's campaign removed criticisms of the strategy from its Web site last month.

Narrowly trailing Obama in national and many battleground state polls, McCain, a 71-year-old decorated Navy veteran and member of the Senate Armed Services committee, has increasingly tried to portray the 47-year-old Obama as lacking the experience and judgment to lead the country in a dangerous world.

Obama, in turn, has criticized McCain for supporting the original Iraq invasion which polls show many voters now consider a mistake. Recently, Obama, who has made Afghanistan a centerpiece of his anti-terrorism strategy, has said the protracted Iraq conflict has drawn needed resources away from Afghanistan where al-Qaida and Taliban forces have shown a resurgence.

"Senator McCain continues to be stubbornly committed to the Bush administration position of an indefinite military presence in Iraq, despite the fact that the Iraqi government is calling for a timeline, despite the fact that the Iraqis are sitting on tens of billions in oil surplus while our economy is struggling at home, despite the impact on our troops and despite the deteriorating situation in Afghanistan," Obama spokesman Hari Sevugan said.