U.S. leaders take our nation to be uniquely chosen by God and to be the "tutor of all other nations." Historian and retired military officer Andrew Bacevich contends that this myth of "American exceptionalism" has led us to transgress the boundaries of nature, the realities of history and the limits of our resources and power. It accounts for decades of mounting failures at home and abroad and prepares our final defeat as a nation.

A longtime critic of our national security, Bacevich, in "The Limits of Power" (Henry Holt, 206 pages, $24), writes with the passion of a father who lost his soldier son in Operation Iraqi Freedom. For Bacevich, American exceptionalism accounts for our tragic descent from being the world's strongest nation in 1945 to today's broken and failing empire. He traces national arrogance from John F. Kennedy's assertive global missions to George W. Bush's doctrine of preemptive warfare.

Bacevich divides the nation's imperious overreach into three main areas. Economically, he says, it takes the form of unlimited consumption, mounting debt, trade imbalances and massive dependencies on foreign oil and credit. Politically, it is directed by beliefs in endless resources and bottomless wealth. The crowning exceptionalist myth, he says, is that America singularly, universally, religiously, altruistically and infallibly serves the cause of freedom. Blinded by these presumptions, national leaders adopt wrong policies, follow ill-conceived plans and choose unrealistic means.

Nowhere, he says, is this as apparent as in national security. Having forgotten what the nation learned in Vietnam, fresh generations of politicians succumb to the illusion that war can serve as a clean and efficient instrument of foreign policy and that soldiers -- as warriors, peacemakers and social workers -- can transform a complex region that has been hundreds of years in the making.

Bacevich, who subscribes to theologian Reinhold Nieburh's national realism, did not write this work to support Barack Obama's election. On the contrary, he judged both Obama and his opponent, John McCain, as adding to the tower of illusion. This dissenting point of view uniquely qualifies Bacevich, in my opinion, to have a seat on any cabinet that presumes to make real change.

Joseph Amato is a professor of history at Southwest Minnesota State University in Marshall and the author of several books.