Twenty years after the end of the cold war, the United States still has about 2,500 nuclear weapons deployed and 2,600 more as backup. The Obama administration, in an attempt to mollify Congressional Republicans, has also committed to modernizing an already hugely expensive complex of nuclear labs and production facilities. Altogether, these and other nuclear-related programs could cost $600 billion or more over the next decade. The country does not need to maintain this large an arsenal. It should not be spending so much to do it, especially when Congress is considering deep cuts in vital domestic programs.

A war with Russia is now unthinkable, conventional weapons are increasingly capable, and the main nuclear threat comes from Iran and North Korea. To have the credibility to try to contain their ambitions, the United States needs to be weaning itself from its reliance on nuclear weapons. Reducing the number of weapons, scaling back unnecessary modernization programs, and delaying or scrapping plans to replace some delivery systems will save billions and help make the world safer.

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President Obama can start by speeding up already negotiated reductions in deployed weapons and committing to further cuts, unilaterally if necessary.

Washington and Moscow pledged in the 2010 New Start treaty to reduce their number of deployed long-range nuclear weapons to 1,550 from 2,200 by 2017. But unless something changes, both countries will increase nuclear spending in coming years, as they replace or upgrade aging nuclear production facilities and delivery vehicles — submarines, missiles and bombers. That makes no sense.