Wasn't it just a few years ago that a sitting Republican vice president declared, “Deficits don't matter”? How quickly times have changed.

President Obama not only declared Dick Cheney's diktat defunct, he also expanded the operative definition of patriotism to encompass belief in balanced budgets. To love your country is to hate red ink. The federal budget deficit and the related national debt now occupy center stage in American politics.

This is surely a good thing. So too is the president's willingness to finger the essence of the problem: a widespread desire for an endless free lunch—people coveting government benefits without a willingness to pay for them.

Obama also performed a useful service in pointing out that any serious effort at deficit reduction will have to target the Big Four: Medicare, Medicaid, Social Security, and national security.

Regarding that last category, the president promises to reassess not only military missions and capabilities, but also America's role in the world. In our post-unipolar moment, such a reassessment is long overdue. Yet to have more than cosmetic results, Obama will have to take on some very sacred cows and some very powerful interests. In the days to come, the president will have ample opportunity to demonstrate the courage and vision that he has thus far kept mostly under wraps.

The president identified the essence of the problem: people coveting government benefits without a willingness to pay for them.

Andrew J. Bacevich is professor of history and international relations at Boston University. His new book, Washington Rules: America's Path to Permanent War, is just out.