As our government teeters on the brink of a shutdown, and Congress and the president haggle over spending cuts, the Pentagon budget should be scoured for places where significant reductions may be made. Not the handful of trims alluded to by Defense Secretary Robert Gates — $78 billion over the next five years, with these savings simply used to shore up spending on other acquisitions — but major cuts to systems that don’t work very well or that are not really going to be needed for decades to come.

Unworkable or unnecessary systems tend to have something in common: their costs are often uncontrollable. A 2009 Government Accountability Office study of 96 major defense acquisition programs found that almost two-thirds of them suffered major cost overruns — 40 percent above contract prices, over all — with average delays of nearly two years. Those overruns totaled close to $300 billion, about the amount of President Bill Clinton ’s last full defense budget request a decade ago.

Listed below is just a sampling of what systems could be ended without endangering America; indeed, abandoning some of them might actually enhance national security. These cuts would generate only small savings initially — perhaps just several billion this fiscal year, as contracts would have to be wound down. But savings would swiftly rise to more than $50 billion annually thereafter.

And there’s plenty more where these came from.