ANALYSIS - U.S. Afghan strategy debate exposes split over price

By Adam Entous

WASHINGTON (Reuters) - U.S. President Barack Obama's review of war strategy in Afghanistan not only has exposed differences between his political and military advisers over how many troops to send, but also what it will cost.

War spending in Afghanistan has more than doubled over the last year, reaching $6.7 billion in June alone, and sticker shock could fuel congressional opposition to another buildup.

The Pentagon has said it likely will need emergency funding for the war but that too many questions remain unanswered to estimate how much.

Rough estimates cited by lawmakers and budget analysts top $40 billion, but competing cost estimates for more troops have stoked confusion on an issue that could have implications for Obama in the run-up to next year's congressional elections.

The White House budget office estimates that it will cost about $1 million for each additional soldier sent to Afghanistan. That means a 30,000-40,000 troop surge, the number favored by several of Obama's top national security and military advisers, would amount to $30 billion to $40 billion a year.

But the Pentagon's comptroller estimates the operating cost of deploying and sustaining one additional troop for a full year in Afghanistan would be half that, at $500,000.

Officials said Obama has asked for more detailed cost breakdowns, as well as timelines for when Afghan security forces could take over for U.S. forces, before deciding on options ranging from 10,000 to 40,000 more troops.

Georgetown University military analyst Christine Fair said the fact that officials are at odds over costs is indicative of the broader discord over war objectives.