The United States-Israeli war on Iran is estimated to have cost Washington $3.7bn so far in its first 100 hours alone, or nearly $900m a day, driven largely by the huge expenditure of munitions, according to new research.

An analysis by Washington-based think tank the Center for Strategic and International Studies (CSIS) underlined the colossal cost of the war, which entered its seventh day on Friday,  as the US attacks Iran with stealth bombers and advanced weapons systems.

Researchers Mark Cancian and Chris Park said only a small amount of the estimated $3.7bn cost of the war in the first 100 hours – or $891.4m each day – was already budgeted for, while most of the costs – $3.5bn – were not.

That meant the Pentagon would likely need to request more funding soon to cover the unbudgeted costs, they said, which was likely to prove a political challenge for the Trump administration and provide “a focal point for opposition to the war,” they said.

Domestic cost-of-living concerns, inflation, and now a knock-on effect of rising gas prices due to the conflict are likely to further diminish support among US citizens for the war. It is also dividing Trump’s “America First” base, which he had promised in his presidential campaigns to not enter “foreign wars”.

Noting that the US Department of Defense had released limited specifics on its operations, the researchers said their analysis drew on Congressional Budget Office (CBO) estimates of the operations and support costs for each unit, adjusting for inflation and unit size, and adding 10 percent for costs of “a higher operational tempo”.

Their analysis said the US had expended more than 2,000 munitions of various types in the first 100 hours of the war, and estimated it would cost $3.1bn to replenish the munitions inventory on a like-for-like basis, with the costs increasing by $758.1m a day.

(Aljazeera)