Donald Rumsfeld is today a discredited and widely reviled figure. Robert Gates, Rumsfeld's successor as Defense secretary, is generally admired for manifesting qualities that Rumsfeld lacked — a willingness to listen not least among them. Yet on one crucial point, the two see eye to eye: Both believe the United States has no alternative but to wage a global war likely to last decades.

In the wake of Sept. 11, 2001, Rumsfeld wasted no time in telling Americans what to expect. "Forget about 'exit strategies,' " he said on Sept. 28, 2001, "we're looking at a sustained engagement that carries no deadlines." Speaking at West Point last month, Gates echoed his predecessor: "There are no exit strategies," he announced. Instead, Gates described a "generational campaign" entailing "many years of persistent, engaged combat all around the world."

Well into the first decade of this generational struggle, Americans remained oddly confused about its purpose. Is the aim to ensure access to cheap and abundant oil? Spread democracy? Avert nuclear proliferation? Preserve the American way of life? From the outset, the enterprise that Gates now calls the "Long War" has been about all of these things and more.

In September 2001, Rumsfeld said: "We have a choice — either to change the way we live, which is unacceptable, or to change the way that they live; and we chose the latter." In this context, "they" represent the billion or so Muslims inhabiting the greater Middle East.

When Rumsfeld offered this statement of purpose and President Bush committed the United States to open-ended war, both assumed that U.S. military supremacy was beyond dispute. A conviction that "the troops" were unstoppable invested the idea of transforming the greater Middle East with a superficial plausibility.

Yet by the time Gates spoke last month, the limits of American military power had long since become apparent. In Iraq and Afghanistan, the opening rounds of the generational campaign are well under way. By historical standards, each is a fairly small war. In neither case, however, have U.S. forces been able to achieve decisive victory. In both cases, barring drastic changes in U.S. policy, fighting will drag on for years to come.

In the meantime, what has the Long War achieved? Not much. Counting on military might to change the way they live isn't working. If anything, the effort has backfired.

Since 2001, the price of oil per barrel has quadrupled, adversely affecting all but the wealthiest Americans. Efforts to spread democracy have either stalled or succeeded only in enhancing the standing of groups like Hamas and Hezbollah. The much-hyped Iraqi nuclear threat turned out to be illusory. To sustain the overstretched American imperium, we are accumulating debt at a staggering clip. And with U.S. soldiers shouldering repetitive combat tours, the strength of our army slowly ebbs away.

Meanwhile, the immediate danger to the American way of life comes not from terrorists but from our own refusal to live within our means. American profligacy, not Islamic radicals, triggered the mortgage crisis underlying our economic distress.

Bluntly, the Long War has proved to be a monumental flop. Yet Gates, channeling Rumsfeld, would have us believe that perpetual war constitutes the sole option available to the world's most powerful nation. This represents a profound failure of imagination. It also misreads our own history.

The United States, with rare exceptions, has demonstrated little talent for changing the way others live. We have enjoyed far greater success in making necessary adjustments to our own way of life, preserving and renewing what we value most. Early in the 20th century, Progressives rounded off the rough edges of the Industrial Revolution, deflecting looming threats to social harmony. During the Depression, FDR's New Deal reformed capitalism and thereby saved it. Here lies the real genius of American politics.

Rumsfeld got it exactly backward. Although we do face a choice, it's not the one that he described. The actual choice is this one: We can either persist in our efforts to change the way they live — in which case the war of no exits will surely lead to bankruptcy and exhaustion. Or we can recognize the folly of generational war and choose instead to put our own house in order: curbing our appetites, paying our bills and ending our self-destructive dependency on foreign oil and foreign credit.

Salvation does not lie abroad. It's here at home.

Andrew J. Bacevich teaches at Boston University and is the author of the forthcoming "The Limits of Power." He wrote this commentary for the Los Angeles Times.