Much money could be saved through better management. However, the far greater problem is over‐​ambitious DOD objectives. Defense is a core constitutional responsibility for the federal government, but that means protecting America, not the rest of the globe.

The Pentagon budget is the price of America’s foreign policy. If Washington hopes to run the world, it must maintain a large and expensive military. In real terms Washington has been spending more on the military than during the Cold War, Korean War, or Vietnam War, all out of proportion to the current threat environment.

Washington’s principal objective should be to defend the U.S. — its people, territory, and constitutional liberties. In some narrow circumstances America’s interest may warrant defending other states. But not today.

In fact, little of what the Department of “Defense” now does actually relates to America’s defense. Washington dominates the globe and is allied with every major industrialized state, save China and Russia. The U.S. mostly subsidizes the defense of its prosperous allies from anyone and everyone.

Terrorism, a vicious, monstrous crime, thankfully poses no existential threat to the U.S. With luck and facing an unprepared foe, terrorists killed 3,000 Americans more than a decade ago. But Osama bin Laden found a repeat performance to be impossible. Terrorism is not World War III.

Moreover, terrorism is not amenable to solution by America’s traditional military tools. In fact, the Bush administration’s promiscuous war making exacerbated terrorism by creating more enemies of America. A smaller international presence would reduce the size of the target on Americans’ backs.

Economic interests are real but rarely warrant war. Stability may be a geopolitical virtue, but does not justify a neo‐​imperial American global presence.

Nation‐​building reflects the triumph of hope over experience, the belief that the Pentagon can remake other societies. Saving lives is appealing, but war is a poor humanitarian tool, witness Iraq.

There is no warrant for preserving what amounts to America’s Cold War military: numerous global alliances, hundreds of military installations, and hundreds of thousands of military personnel around the world.

The worst argument for military spending, offered by Republican politicians otherwise skeptical about government “stimulus” spending, is that cutting outlays would destroy jobs. If economic growth is the objective, the money should be left in private hands for saving and investment.

In any case, Washington no longer can afford to play the role of global cop. America’s $16.8 trillion national debt is just the start; unfunded liabilities run Uncle Sam’s total tab to more than $220 trillion.

Military outlays account for a smaller percentage of the GDP than during World War II and the Cold War, but America’s current GDP is 15 times as large as in 1940 and more than 11 times as large as in 1950. Thus, in terms of real resources the 4.6 percent of GDP devoted to the military last year was equivalent to 68 percent of the 1940 GDP.

Entitlement outlays will grow more quickly than military expenditures in coming years, but the fact that government devotes too much to Social Security is no argument for spending too much on the military. The U.S. cannot afford any budget sacred cows.

Despite the despairing rhetoric of Pentagon hardliners, the sequester is but a scalpel when a meat‐​ax is required. Real, inflation‐​adjusted expenditures jumped 76 percent during the Bush administration. They continued rising, though less swiftly, during the Obama administration.

Yet expenditures should come down naturally with the end of the Iraq war and imminent end of combat operations in Afghanistan, which together ran around $150 billion a year. If fully applied, figures Veronique de Rugy of the Mercatus Center, the sequester will only reduce real outlays to the 2006 level. That will still be greater than spending during the Cold War, when there was a Soviet Union, Warsaw Pact, and Maoist China.

Washington is on an “unsustainable” fiscal course, warned the Congressional Budget Office. Hard decisions are required. Which means big spending cuts. Including at the Pentagon.