The cost of U.S. military operations in Iraq and Syria (Operation Inherent Resolve) to combat the Islamic State of Iraq and the Levant (ISIL) since August 8, 2014 reached $2.11 billion in April 2015, the Department of Defense (DoD) reports. This averages out to $8.6 million a day.
In September 2014, DoD reported that the cost of operations against ISIL was averaging between $7.5 million per day. DoD has pointed out that the daily cost of operations fluctuates as the level of effort changes.
These costs are being funded from the Overseas Contingency Operations (OCO) approved by Congress. The administration requested $3.4 billion for Operation Inherent Resolve (OIR) in FY2015. For FY2016, the OCO request includes $4 billion to support OIR plus another $1.3 billion to train Iraqi forces (including Kurdish forces) and moderate Syrian opposition, Secretary Ash Carter told the Senate Appropriations Defense Subcommittee earlier this month.
DoD reports that 6,981 close air support, escort, and interdiction air sorties were conducted in 2014 and 5,668 such sorties have been carried out in 2015 as of March 31.
DoD has emphasized that operations against ISIL, especially airstrikes, involve contributions from partner nations. According to a DoD news release, “coalition nations conducting airstrikes in Iraq include the United States, Australia, Belgium, Canada, Denmark, France, Jordan, the Netherlands and the United Kingdom. Coalition nations conducting airstrikes in Syria include the United States, Bahrain, Canada, Jordan, Saudi Arabia and the United Arab Emirates.”