QUOTE OF THE DAY…. Sen. Richard Lugar (R-Ind.), the ranking Republican on the Senate Foreign Relations Committee and arguably the only GOP senator with any credibility left on international affairs, appears to be deeply skeptical of the U.S. efforts in Libya. That probably won’t do him any favors in the Republican cloakroom.

But there was one line in particular he offered on “Face the Nation” this morning that stood out for me.

Lugar warned that the U.S. is investing huge sums of money in a foreign endeavor at a time when the domestic economy is still struggling.”It’s a strange time,” he said. “Almost all of our congressional days are spent on budget deficits, outrageous problems. Yet, at the same time, all of this passes, which is a very expensive operation.”

Wait, you mean military operations aren’t free?

We’ve grown accustomed to simply leaving costs out of the equation when evaluating the merit of national security decisions. For much of the political establishment, it seems somehow gauche — we’re dealing with a combat situation, which necessarily means money is no object.

But to borrow a cliche, missiles don’t grow on trees. We’ve spent the last two months hearing Republican officials tells us, ad nauseam, that “we’re broke.” In fact, we’re so broke, we have no choice, they tell us, but to decimate funding for education, medical research, infrastructure, job training, and homeland security, among other things, even if it makes the jobs crisis much worse. “So be it,” Speaker Boehner tells us.

Apparently, however, we’re not that broke. At least not broke enough to think twice about whether to engage another foreign enemy.

Truth be told, I’m not especially concerned about the costs of this operation, either. Whether “Operation Odyssey Dawn” is a good idea is a question worth considering in great detail, but when evaluating the merits, costs aren’t exactly the first question I’m inclined to ask.

Then again, I’m not a deficit hawk who’s been telling the nation that spending more money — on anything — will likely cause the end of civilization as we know it. Those who have been making just such a case may want to take a moment to explain why we can’t afford to fund Head Start centers, but the price of Tomahawk cruise missiles aren’t much of a concern.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.