The Obama administration says that we need to end what it calls “the era of austerity” in Washington. Notably excluded from this admonition is the one department of government that is actually experiencing austerity worthy of the name.

Defense Secretary Chuck Hagel unveiled a military budget that will reduce the U.S. Army to pre-World War II levels. The spin is that this will be a smarter force better suited to 21st-century challenges, but everyone knows that it is all about accommodating the trillion dollars in defense cuts adopted during the recent Beltway budgetary wars.

The Pentagon has been a bipartisan target of opportunity. Democrats oppose defense spending because it’s defense spending; Republicans oppose it because it is spending.

We obviously aren’t at the same point as the British in the 19th century, when Bismarck scoffed that if the British army invaded, he’d have it arrested. But 570,000 troops were barely enough to fight the Iraq and Afghanistan wars, and the Hagel budget will take us to 450,000, or — if the defense sequester isn’t further relaxed — even fewer.

Most defense secretaries aspire to be the next George Marshall. Secretary Hagel evidently wants to be the next Harold Brown, who presided over the Carter-era hollowed-out military.

It is not quite true that the cuts are undertaken without any strategic thought. The Obama administration’s strategic thought is … that we need no strategic thought. It is said that the British acquired an empire through a fit of absent-mindedness. We are losing our global influence the same way. Because we can’t be bothered.

Understandably, we don’t want to fight another grinding ground war. But this doesn’t mean we won’t have to, or we won’t experience other nasty surprises. It is an unfortunate part of the American tradition to convince ourselves, when we find it convenient, that the world is not a dangerous place that always demands our attention, or else.

In 1939, the United States had an Army of 185,000 men on the cusp of history’s most cataclysmic war. We believed conflicts could always be worked out among nations, and that war served no one’s interests, and so it was a thing of the past.

“It was odd,” the late historian Stephen Ambrose writes, “that a nation that had come into existence through a victorious war, gained large portions of its territory through war, established its industrial revolution and national unity through a bloody civil war, and won a colonial empire through war, could believe that war profited no one.”

But so it did. As soon as World War II ended, we embarked on a carelessly precipitous demobilization that junked one of the most fearsome Western armies ever assembled. Just having liberated Europe, we still managed to find ourselves unprepared for the onset of the Korean War.

Defenders of the current defense cuts say that we still spend more on our military than anyone else in the world. True, but we aren’t a mere regional power. Unless we want to outsource patrolling the global sea lanes to China and the security of Europe to Russia, we will always have to spend substantially more than anyone else does.

Our allies aren’t in any position to pick up the slack. When the French army wants to go anywhere, we have to fly it. The entire British navy is smaller than the fleet sent to take back the Falklands in the 1980s.

President Barack Obama is a devoted believer in the efficacy of government spending as government spending — on everything but defense. In 2009, it was $800 billion for stimulus but not a cent for defense. In his wisdom, he is perfectly content to slash a function of government that is indisputably constitutional, that is the basis of our freedom, and that is, relative to domestic entitlements, a drop in the budgetary bucket.

We may not regret it this year or the next. But regret it we will.

Rich Lowry can be reached via e-mail: comments.lowry@nationalreview.com.