Nukes

The reason that all out nuclear war is unlikely are many but the biggest deterrent are the Ohio class submarines called boomers. The entire fleet of 18 subs could carry as many as 24 missiles on each sub and each missile has12 warheads. That means 5,184 nuclear bombs and each bomb contains 200 kilotons of TNT which is 30 times larger than the bombs used against Japan in WW 2. Combine this with the accuracy with which these missiles have and every city in the US with a population of over 50,000 could be totally destroyed. At any given time the location of these subs is secret and they stay at sea mostly under water for 77 days at a time and then come in for 35 days and back out again. If the United States were completely wiped out in a surprise attack the subs would counter attack. The only way this whole scenario would happen is if someone wanted to destroy their own whole country. It is not likely that there could be a little nuclear war using tactical weapons without escalating into a full out war as this would remove the advantage of a surprise attack. There always remains the very small possibility that some insane person could gain control of the box but that is highly unlikely but not impossible. This does not take into account the 400 Minute Man land based missiles and each contains three 200 kiloton warheads.