U.S defenses against nuclear war can be breached to murder our citizens if nuclear missiles are fired at the U.S. Russia has missiles and bombs that can kill millions in a single blast. North Korea has bombs that can kill hundreds of thousands in a single blast, and North Korea continues to improve nuclear missiles and nuclear bombs. Both nations have many nuclear warheads to be used in a nuclear war. Tests of U.S. nuclear missile defenses have experienced failures, and such a failure during a  nuclear weapon attack can kill thousands or hundreds of thousands of people.