April 1980: As U.S. special forces abandoned their staging base deep in the Iranian desert, tragedy struck. A Marine helicopter hit an Air Force C-130 loaded with fuel. The giant fireball killed eight. The attempt to rescue 50 American hostages in Tehran collapsed in failure and humiliation.

The secret mission had stretched the Marine helicopters to the limit. They were not the best tool for the job, but they were the best the military had. Anticipating some miscues and mechanical failures, the Pentagon had dispatched extra ships, but it wasn’t enough to overcome the challenges encountered.

The Desert One debacle was almost a decade in the making. The military had ramped up for Vietnam without building up. Units in Europe were gutted to fill platoons in Vietnam. Major equipment modernization programs were jettisoned to help pay for the war. And as soon as hostilities ended, Washington took a “peace dividend,” eviscerating the Pentagon’s budget.

America’s military went “hollow.” It looked fine on the briefing charts and sounded great in congressional testimony, but the services lacked the manpower, training, readiness and equipment to protect U.S. interests worldwide. By 1980, even our most elite outfit — the super-secret Delta Force — lacked the stuff it needed to do the job. The fires at Desert One were a beacon of unpreparedness.

When ordered to cut spending quickly, militaries have few options. Manpower and equipment purchases consume the lion’s share of the budget. But troops can’t be let go at the drop of a hat, and even weapons contracts can’t be terminated overnight. (And terminations usually involve huge penalty payments anyway.) The Pentagon will have to resort to cuts in training, missions, maintenance and other accounts. Such cuts quickly degrade military capabilities.

The Army could well become the hollow force poster child. After 9/11, the service had to build up what it calls Army Force Generation — ARFORGEN. It added troops, equipment and training so it could rotate fresh, trained units and have them ready for worldwide deployment. ARFORGEN was built to keep the Army from burning out like it did in Vietnam. The initiative cost U.S. taxpayers some $40 billion. By and large, it has worked well.

Now in the name of fiscal responsibility, the Army is supposed to “share the burden” of reducing federal spending. The belt-tightening could well force the Army to abandon ARFORGEN. This would be like abandoning one’s house after the mortgage is already paid off on the grounds that the electric bill is too high. Is it smart to walk away from a home worth $200,000 to save a few bucks a month on utilities?

President Barack Obama insists on reducing the readiness of the military forces needed to protect us. Yet at the same time he insists that Congress must pass “now” a new $447 billion jobs bill that will add little to the economy other than more debt.

“Defense on the cheap” is neither wise military policy nor smart economics. Moreover, job No. 1 of the presidency is to assure the security of U.S. citizens, safeguard our sovereignty and protect our interests around the world.

Squeezing money from the troops while spending it on corporate cronies (think Solyndra), political allies (think unions) and other special interests is no fair trade for America’s military security.

James Jay Carafano is a senior research fellow for national security at The Heritage Foundation.