Armies are like newspapers. They have become 21st-century anachronisms. To survive, they must adapt. For the press, that means accommodating the demands of the Internet. For the United States Army, it means adjusting to a changing security environment. Nostalgia about a hallowed past is a luxury that neither armies nor newspapers can afford to indulge.
So the hand-wringing triggered by Defense Secretary Chuck Hagel's plan to reduce the Army's size, while predictable, is beside the point. Yes, those cuts would leave the United States with its fewest active-duty soldiers since the eve of World War II.
This isn't 1940. Moreover, as an instrument of coercion, that smaller army would be more lethal than the much larger one that helped defeat Nazi Germany and imperial Japan. Given a choice between a few hundred of today's Abrams tanks and a few thousand vintage Shermans, Gen. George Patton would not hesitate to choose the former.
More relevant questions are: Do we need even a few hundred tanks? And for what? In its 2012 report to Congress, the Army's senior leadership described the service as "The Nation's Force of Decisive Action." In the 2013 version, they "guarantee the agility, versatility and depth to Prevent, Shape and Win."
Yet to judge by outcomes, the Army is not a force for decisive action. It cannot be counted on to achieve definitive results in a timely manner. In Afghanistan and Iraq, actions that momentarily appeared to be decisive served as preludes to protracted and inconclusive wars. As for preventing, shaping and winning, this surely qualifies as bluster - the equivalent of a newspaper promising advertisers that it will quadruple its print circulation.
Washington's preoccupation with budgets provides Army leaders - and the entire national security establishment - an excuse to dodge core questions. The most pressing: What should the nation expect of its armed forces?
After the Cold War and especially after the attacks of Sept. 11, 2001, expectations of what the U.S. military should be able to accomplish expanded considerably. Defense per se figured as an afterthought, eclipsed by the conviction that projecting power held the key to transforming the world from what it is into what Washington would like it to be: orderly, predictable, respectful of American values and deferential to U.S. prerogatives.
The "Global War on Terror" put that proposition to the test, with disappointing results. Putting boots on the ground produced casualties and complications, but little by way of peace and harmony. It did nothing to enhance the standing and reputation of the United States. And as a means to engineer positive political change, America's Army proved sadly wanting. That's not a knock against our soldiers. They performed admirably, even if the same cannot be said for those who conceived and mismanaged the wars our soldiers were sent to fight.
Americans today are not inclined to indulge this experiment further. With his widely noted preference for drones and Special Operations forces, President Barack Obama has tacitly endorsed the public's view - even if his improvised way of war is devoid of any serious strategic rationale.
The principal military lesson of the Global War on Terror affirms what ought to have been the principal lesson of the Cold War: Force held in readiness has far greater political utility than force expended. Armies are well suited to defending and containing. But invading and occupying countries are fraught with risk.
It's the Bush Doctrine, just inverted: Rather than engaging in preventive war, commit troops only after exhausting every other alternative. As long as that approach pertains - may it do so for many decades - the projection of U.S. military might will come in the form of bombs and missiles, falling under the purview of naval and air forces.
What role, then, remains for the United States Army? The honorable and necessary one of defending this country. For that task, absent the emergence of a major Mexican or Canadian threat, a smaller Army should serve just fine.
Andrew Bacevich is a professor of history and international relations at Boston University.