DEFENSE SECRETARY Chuck Hagel on Wednesday released a sobering report on the deep funding problems looming at the Pentagon, which is on track to fall tens of billions short of what it needs to fulfill the strategic mission that President Obama has articulated for the national defense. The same day, Mr. Obama told congressional Democrats that the Pentagon should get no more attention than many other areas of the budget also subject to the punishing automatic spending cuts known as sequestration. That can’t be the final answer from the commander in chief.

Mr. Obama’s latest budget proposes $150 billion in defense cuts over 10 years, which Mr. Hagel claims could be managed. Sequestration, however, requires $500 billion in cutsover 10 years.

Mr. Hagel’s review estimates that closing unnecessary facilities and duplicative offices could yield $60 billion over a decade. Reasonable measures to rein in personnel costs, which have soared 40 percent above inflation for more than a decade, might yield $50 billion over 10 years, while harsher personnel measures might produce $100 billion. The Pentagon reckons it can safely slash the size of some forces, such as the cargo plane fleet, the ground and tactical air forces and the standing army and reserves a bit.

But even assuming Congress would permit what Mr. Hagel sees as rational cuts — and that is unlikely — these wouldn’t come close to satisfying the demands of the sequester. Instead, the Defense Department would have to choose between maintaining technological sophistication or numerical strength. If it chose the former, Mr. Hagel explained, it would keep “a force that would be technologically dominant but would be much smaller and able to go fewer places and do fewer things, especially if crises occurred at the same time in different regions of the world.” The other option would result in a larger force capable of international deployment but with aging weapons systems that rivals would have an easier time matching.

Deputy Defense Secretary Ashton Carter said in testimony on Thursday that either way would “mark a significant departure from the missions our nation has been accustomed to being able to accomplish.”

The entire sequester, hitting defense and non-defense, was bad policy when lawmakers passed it, it was bad policy when they let it begin, and it remains bad policy. The president is right to press for the whole thing to end, along with Congress’s indefensibly short-term approach to budgeting. Political tactics may compel him for the moment not to give national security special consideration, given House Republicans’ intransigence.

But Mr. Obama ultimately can’t act as though the Defense Department’s sequester cuts are equivalent in consequence to every other item in the budget. The country’s defense is a core responsibility of the federal government, and its armed forces are critical to the nation’s ability to exert leadership, maintain alliances, defend human rights and preserve the nation’s safety.