The potential U.S. military strike in Syria is raising moral and political quandaries for Washington. Does it raise a fiscal problem as well?
After all, the Pentagon's budget has been curtailed recently in ways that top officials have warned would create a "hollow" force over the next decade.
However, defense budget experts say, a military strike in Syria is not likely to present a major burden for the federal budget, as long as it's limited and doesn't involve troops on the ground.
"The immediate budget implications for this are quite small," said Todd Harrison, a senior fellow at the Center for Strategic and Budgetary Assessments.
For one thing, the ships, missiles and bombers that the United States might use have already been purchased, said Lawrence Korb, a former assistant secretary of defense who is now a senior fellow at the Center for American Progress. And the training and salaries of the military personnel operating them have already been included in the defense budget.
So the initial costs of a military strike might be a few hundred million dollars to pay for things like fuel, Harrison said.
That's a rounding error in the context of a defense budget that tops $500 billion annually.
In the next year or two, the cost could rise as the military seeks to replace the missiles and bombs it uses in Syria. One Tomahawk missile, for example, costs about $1.5 million.
But replacing even several hundred of them is not likely to unhinge the defense budget -- which is $507 billion even after accounting for a 6.7 percent reduction in defense spending so far this fiscal year.
Nor would it put the Pentagon at risk of violating the spending caps set under the so-called sequester.
That's because the sequester -- the automatic, across-the-board budget cuts that Congress criticized but failed to replace -- doesn't apply to a lot of spending for military actions. For example, supplemental funding to the defense "base" budget and money for "overseas contingency operations" are exempt from the sequester, Korb and Harrison noted.
The concern, of course, is that involvement in the Syrian conflict could morph into a yearslong engagement.
"That's when the costs go through the roof," said Harrison.
But right now, any financial cost is unknowable, since it's unclear exactly what course of action the United States will take and what the outcome will be.