The war in Afghanistan will consume more money this year alone than we spent on the Revolutionary War, the War of 1812, the Mexican-American War, the Civil War and the Spanish-American War  combined.

A recent report from the Congressional Research Service finds that the war on terror, including Afghanistan and Iraq, has been, by far, the costliest war in American history aside from World War II. It adjusted costs of all previous wars for inflation.

Those historical comparisons should be a wake-up call to President Obama, underscoring how our military strategy is not only a mess  as the recent leaked documents from Afghanistan suggested  but also more broadly reflects a gross misallocation of resources. One legacy of the 9/11 attacks was a distortion of American policy: By the standards of history and cost-effectiveness, we are hugely overinvested in military tools and underinvested in education and diplomacy.

It was reflexive for liberals to rail at President George W. Bush for jingoism. But it is President Obama who is now requesting 6.1 percent more in military spending than the peak of military spending under Mr. Bush. And it is Mr. Obama who has tripled the number of American troops in Afghanistan since he took office. (A bill providing $37 billion to continue financing America’s two wars was approved by the House on Tuesday and is awaiting his signature.)