Expert sounds alarm on uncertainty after expiring nuclear weapons treaty

For the first time in more than 50 years, the world's largest nuclear powers, the U.S. and Russia, do not have an agreement limiting their long-range nuclear arsenals. Margaret Brennan explains what this could mean in an already dangerous world.

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Expert sounds alarm on uncertainty after expiring nuclear weapons treaty For the first time in more than 50 years, the world's largest nuclear powers, the U.S. and Russia, do not have an agreement limiting their long-range nuclear arsenals. Margaret Brennan explains what this could mean in an already dangerous world.