“As long as we have ICBMs, there will be the possibility of the President launching them in response to a false alarm. Since the ICBMs are known in fixed locations, they can be attacked and we presume that any nuclear attack on the United States would include attacks against those ICBMs. And therefore, we have a policy called launch-on-warning which means if we have a warning of an attack, then the President would be notified and he has the option of launching those ICBMs before the attack actually reaches its targets.
Now the danger with that, of course, is that if the warning of attack is wrong, if it’s a false alarm, and the President actually launches the ICBMs, he will have no way of calling them back or destroying them in-flight if, in fact, the alarm is a false alarm.
So the problem with the ICBMs fundamentally is that if we get a false alarm and the President launches the ICBMs, we will have started a nuclear war capable of ending civilization based on a mistake, based on an accident, based on a false reading. That is not very likely to happen- it’s a low probability- but a low probability with a very, very high consequence. So that’s my concern with the ICBM program and it’s a fundamental concern; as long as we have ICBMs, there will be the possibility of the President launching them in response to a false alarm.”