Ten years ago, the United States and Russia signed the New START treaty—a nuclear arms control agreement that we, as the heads of our governments’ respective delegations, helped negotiate. Since then, New START has played a central role in keeping the peace and preventing a dangerous arms race between the two countries that together possess 90 percent of the world’s nuclear weapons.

Now, however, New START is in trouble: without action to extend it, the treaty will expire in February 2021. Its demise would have worrying implications for the security of the United States, of Russia, and of the world. It could bring a return to nuclear competition and spark mutual suspicion that would push the world to a level of nuclear risk unseen for decades.

Read full article at Foreign Affairs