A Tomahawk missile costs $1.4 million. If you don't know that, you haven't paid attention to the debate over the Libya War.

The war is America's first conflict initiated against the backdrop of $1 trillion deficits, and as such practically every strike is subject to the accountant's bean-counting. Our first fusillade of 160 cruise missiles, we are told, cost hundreds of millions of dollars alone. Even Indiana's Sen. Richard Lugar, a Republican establishmentarian and internationalist of long standing, argues the cost of the war is too damn high. "Who has really budgeted for Libya at all?" he asks.

Yes, by all means, the next time we're faced with an international crisis requiring a hair-trigger response saving the rebellion once it was reeling back toward its base in Benghazi required action in a matter of days let's first have a hearing of the Senate Budget Committee and a cost estimate from the Congressional Budget Office.

There are compelling reasons to oppose the Libya War. Cost is not one of them. That we are now to consider every act of U.S. foreign policy merely as a line item in the federal budget is a sign of fiscal monomania and superpower degeneracy, not to mention a failure in basic math.

In the late 1960s, defense spending was about 10 percent of GDP, and so was nondefense spending. Since then, defense spending has fallen roughly in half as a proportion of GDP, while nondefense spending has roughly doubled. In our long-term fiscal crisis, guns are a pittance compared with all the butter.

Libya would have to be a conflagration rather than a brush fire to move the fiscal needle. About those Tomahawk missiles: Scott Lilly of the Center for American Progress points out that there are 3,500 Tomahawks in our arsenal. We buy about 200 more each year to maintain our production capability. In short: We can spare a few for Moammar Gadhafi. As for the cost of the ships and the planes involved, they were already deployed in the region anyway.

As a country, we haven't had happy experiences with stinting on defense, whether prior to the War of 1812, World War II or the Korean War. It may not seem fair that we have to shoot the Tomahawk missiles and fly the B-2 bombers of the Libya War, but would we really prefer that someone else matched our capabilities, or that we didn't have the hardware to respond rapidly in urgent circumstances?

The world can't always be counted on to throw up challenges precisely calibrated to our preferences. When someone suggested at the Constitutional Convention that the standing army not exceed 3,000 men, George Washington illustrated the folly of the proposal with wry countermotion stipulating that "no foreign enemy should invade the United States at any time, with more than 3,000 troops."

The reaction against the Libya War exhibits symptoms of imperial exhaustion, the feeling that the world is too much with us and we can't expend the energy or resources to cope with it now. An understandable sentiment, perhaps, but nothing good will come of it.

Rich Lowry is editor of the National Review.

(c) 2011 by King Features Synd., Inc.