WASHINGTON - The widening US air war against Islamic State jihadists in Syria and Iraq will cost more than the 2011 Libya conflict and the price could rise to a billion dollars a month, experts said Thursday.
The Pentagon estimated in August the operation in Iraq could cost an average of about US$7.5 million (S$9.5 million) a day, but even US defence officials acknowledge that estimate is low and came before President Barack Obama ordered a broader campaign extending into Syria.
Taking into account the larger-scale air operations over Syria, the wear and tear on hi-tech hardware and the cost of even a small troop contingent in Iraq and the region, some budget analysts and former officials say the war's annual cost could rise to more than US$10 billion.
"I think you're talking double-digit billions, not single-digit billions," Jim Haslik, a senior fellow at the Atlantic Council, told AFP.
On the first night of air strikes against the IS group in Syria this week, the United States launched 47 Tomahawk cruise missiles from ships at sea and deployed sophisticated F-22 Raptor fighter jets.
Each missile costs about US$1.5 million and the F-22 jets cost roughly US$68,000 an hour to fly.
The rising costs, however, pale in comparison to the massive funding required to cover the drawn-out counter-insurgency campaigns in Iraq and Afghanistan over the past decade.
"It's still small relative to Afghanistan," said Todd Harrison of the Center for Strategic and Budgetary Assessments.
The bill for the war in Afghanistan comes to a billion dollars a week. The 2003 invasion of Iraq and the subsequent occupation through 2011 cost more than a trillion dollars, according to some estimates.
Even with Obama's vow not to send ground troops into combat, 1,600 soldiers are now in Iraq guarding US diplomats, coordinating air raids and advising Iraqi forces.
Most analysts and former commanders expect that number to creep up as the war continues, adding more costs.
And the White House has stressed that the mission to smash the Islamic State group will likely take months, if not longer.
"It's too soon to say what we will be able to accomplish, and how quickly we might be able to accomplish it," said Harrison.