Defense

Cost of modernizing U.S. nuclear weapons to fall to next president

The most vulnerable elements of the modernization plans are a long-range standoff weapon, or LRSO – a nuclear-capable cruise missile launched from an aircraft – and new land-based intercontinental ballistic missiles (ICBMs).

Ten U.S. senators, including Elizabeth Warren of Massachusetts and Bernie Sanders of Vermont, called on President Barack Obama in July to cancel the LRSO, saying it "would provide an unnecessary capability that could increase the risk of nuclear war."

Some Pentagon officials and defense experts have said the cruise missile would be a hedge against improved air defenses that are difficult for even a stealthy bomber to penetrate.

A Clinton or Trump administration also could cut the number of land-based ballistic missiles below the 400 currently planned or delay a new missile by extending the life of the current Minuteman IIIs, which each carry a warhead with an explosive yield of at least 300 kilotons, 20 times more powerful than the atomic bomb dropped on Hiroshima, which killed an estimated 140,000 people.

The United States is one of five nuclear weapons states allowed to keep a nuclear arsenal under the Nuclear Non-Proliferation Treaty. The others are Russia, Britain, France and China.