WASHINGTON - President-elect Barack Obama's administration needs to monitor war spending much more closely than the current White House has, according to a new study that criticized President Bush's approach to funding the Iraq and Afghanistan wars - a bill that is projected to approach nearly $1 trillion next year.

Even with declining troop numbers in Iraq, the direct price tag of the two wars could grow as high as $1.7 trillion by 2018, the Center for Strategic and Budgetary Assessments reported last week. The defense think tank's figure does not include potentially hundreds of billions more in indirect economic and social costs, such as higher oil prices and lost wages.

The war in Iraq alone has already cost more in inflation-adjusted dollars than every other U.S. war except World War II, the center found.

Defense Secretary Robert M. Gates, who will stay on under Obama, has made clear that the incoming administration will scrutinize defense spending, which has mushroomed since 2001 as a result of the wars and related costs.

"There clearly is going to be very close scrutiny of the budget," Gates said earlier this month. "We need to take a very hard look at the way we go about acquisition and procurement."

The center agreed and attributed the ballooning budgets to the Bush administration's unprecedented decision to fund the wars through giant emergency spending measures rather than appropriations requests.