In an effort to start making sense of what is an indisputably confusing situation, we asked some of the most thoughtful people we know the question: How will America change as a result of the economic downturn? Here's Andrew J. Bacevich, a professor at Boston University and the author of The Limits of Power: The End of American Exceptionalism.

We can now finally chuck overboard all of the bloated and self-congratulatory language of the post-Cold War era: the claims made of a Sole Superpower serving as the Indispensable Nation during a Unipolar Moment at the End of History. Each and every one of these notions was pernicious from the moment it was uttered. Events have now decisively demonstrated each to be absurdly false.

When it comes to statecraft, the chief lessons of the Bush era are these: Arrogance and hubris have revealed the very real limits of American global leadership; recklessness and ineptitude have revealed the limits of American military power; a foolish and self-indulgent unwillingness to live within our means has now made clear the limits--and the fragility--of American prosperity. We may choose to ignore these lessons--neoconservatives will insist upon it--but the consequences of doing so will be severe.

A season of reckoning is upon us. To say that is not to imply that the United States is now condemned to an irreversible downward spiral. It's not. It is, however, time for us to clean up our act and to put our own house in order. When it comes to foreign policy, that means restoring a balance between our commitments and the means that we have at hand to meet those commitments.

And that means, above all, revisiting and revising the deeply defective notion of open-ended "global war"--World War IV!--as the proper response to the threat posed by violent Islamic radicalism. We need a new framework for national security strategy, one that junks the global war on terror in favor of an alternative that is affordable, sustainable, and relevant to the variety of challenges that we face. Realism and modesty must become our watchwords.

One might think that a presidential campaign would provide the occasion to debate strategic alternatives. Unfortunately, there is precious little evidence that the current campaign is going to produce such a result. In that regard, the final lesson of the Bush era has been to demonstrate just how vapid and unimaginative our politics have become.

--Andrew J. Bacevich