Air war against Islamic State group cost $5.5 billion

The air war against the Islamic State group has cost the American taxpayer $5.5 billion, roughly $11.2 million per day, a $2 million increase since June, according to the latest Defense Department data.

The Air Force accounts for $3.75 billion — nearly 70 percent — of that cost, about $7.7 million a day since the U.S. began launching airstrikes in August 2014.