WASHINGTON — The U-2 spy plane outlasted the Cold War, outlived its successor and proved crucial a half-century ago when two superpowers were on the brink of nuclear war.

But defense cuts now threaten to knock the high-flying reconnaissance aircraft out of the sky.

The Air Force wants to gradually retire the fleet of 32 “Dragon Lady” planes, which can soar to an altitude of 70,000 feet, collect intelligence on North Korea and Russia and rapidly send the data to U.S. commanders. That’s a critical capability, given North Korea’s unpredictable leader, Kim Jong Un, and Russia’s emboldened president, Vladimir Putin.

The Air Force says the unmanned aerial vehicle Global Hawk can do the job, and in an era of smaller, deficit-driven budgets, the Pentagon cannot afford both the plane and the drone.

Skeptical lawmakers have challenged the Air Force’s proposal to ground the resilient U-2, the long-winged, all-weather manned aircraft with sensors and cameras.