ISISCost of U.S. war on ISIS reaches $780 million

The cost of the war against the Islamic State (ISIS) Islamist group has totaled at least $780 million, according to a new estimate, as U.S. warplanes and drones continued to strike Isis positions in Iraq and Syria on Monday and Tuesday.

Defense Secretary Chuck Hagel said on Friday that the U.S. military is spending up to $10 million a day and will likely request more money from Congress to fund the war. The attacks on ISIS began 8 August, and before they were expanded to include targets in Syria, the Pentagon estimated the daily war costs at $7.5 million.

The Center for Strategic and Budgetary Assessments (CSBA), an influential Washington, D.C. think tank, estimated on Monday that the air war has already cost between $780 million and $930 million between 8 August, when it began, and 24 September.

The Guardian reports that Congress has not voted on going to war, outside of authorizing the military to train a proxy Syrian rebel ground force, and will not do so until after the November midterm elections at earliest.

The CSBA priced out estimates of a range of options proposed by politicians, retired military officers, and pundits for escalating the war. What it called a “moderate level of air operations,” involving 2,000 “deployed ground forces” — a level slightly higher than the 1,600 ostensibly non-combat security and “advisory” U.S. forces in Iraq now — would total as much as $320 million each month and $3.8 billion annually.

Should the United States deploy a ground force of 25,000 U.S. troops, as advocated by Frederick Kagan, the Iraq surge architect, annual costs would run “as high as $13 billion to $22 billion.” An air campaign with a higher operational tempo and a 5,000-troop deployment would cost between $350 million and $570 million per month and $4.2 billion to $6.8 billion each year.

General Martin Dempsey, the chairman of the joint chiefs of staff, earlier this month said U.S. ground combat alongside Iraqi and Kurdish forces was possible. He and Hagel on Friday anticipated asking Congress for additional money in the military’s baseline budget, which already stands at about $500,000, excluding nearly $59 billion in requested war funding, mostly for Afghanistan.

That war funding is “gas money,” Dempsey said, above and beyond the difficulties that a new and unanticipated war are likely to have on the funding assumptions of the military services.

The United States is trying to help build Iraqi and Kurdish ground forces to reclaim territory from ISIS, but the plan to raise a Syrian proxy force is not expected to create a battle-capable force for nearly a year. Dempsey on Friday estimated that rolling back Isis in Syria will require a proxy force of between 12,000 and 15,000.

The White House requested $500 million to train and arm Syrian rebel forces, but the Guardian notes that it is unclear how many rebels that total will initially fund. The Pentagon estimates it can train up to 5,000 “vetted” Syrians within a year, a figure suggesting the training might run to $1.5 billion for a force of 15,000, excluding the costs of keeping that force viable in the field.

— Read more in Todd Harrison et al., Estimating the Cost of Operations Against ISIL (CSBA, 29 September 2014)