You may have heard of the Doomsday Clock, which purports to inform us all how close the world is to a nuclear holocaust. In fact, it is mostly a convenient propaganda tool for those in favour of disarmament at any cost. No one really knows what conditions are likely to lead to a nuclear war, and nuclear physicists are in a worse position to judge than historians or political scientists. It has recently been extended to include the threat of climate disaster, as though to emphasize its political motivations.
The Doomsday Clock presently shows us at 5 minutes to midnight, which is closer to catatrophe than it has been since 1984, and one of the closest points in its history (see the wikipedia entry for a timeline). For the first time in my life, I believe they may be underestimating the threat. I don't expect a complete global nuclear war anytime soon, but I think the chance that nuclear warheads will be used in combat is higher than it has been since 1945.
The Cold War, especially in the 1950's and 60's, was a frightening time. Two hostile powers both possessed nuclear weapons, and there was no telling what little quarrel might escalate into a full war. At least, however, the nuclear powers were restricted, had full control of their weapons, and behaved somewhat rationally. I never considered the doctrine of Mutually Assured Destruction (MAD) a satisfactory basis of defense, but its logic did probably prevent an outright nuclear war. Although the Soviet Union was an aggressive power, it wanted to dominate the world, not destroy it, and its leaders drew the appropriate conclusions from that.
The same logic no longer applies. Israel, South Africa, Pakistan, and India also have nuclear weapons (along with China, France, and the U.K.), North Korea has now demonstrated its capacity to produce them, and Iran is not far behind. There are more nuclear weapons in more places than ever before, and their control is more dubious. We have recently seen the frightening prospect of advancing Taliban armies seizing control of Pakistan and at least some of its nuclear weapons. The fate of Russia's nuclear arsenal has also been insecure, and I am told that the Russians cannot account for all the missiles in their inventory from before the fall of Communism. These, or others, might end up in the hands of "non-government actors" -- terrorists -- at any time.
But what most concerns me now is not the terrorists (that is a longer-term threat), but the governments that produced the weapons. North Korea could probably destroy much of South Korea, or even Japan, and Iran may soon be in a position to destroy Israel. One reads that they are held in check only by the certainty that they would be themselves nuked by America in response -- the logic of MAD again. But would they?
Let's suppose that Iran sends a missle or two to Israel. It's a small, flat country, so it wouldn't take much to make it uninhabitable (it's barely habitable as it is). Israel has its own nuclear arsenal, but it cannot depend on getting a counterstrike: the distance from Iran is too small, and the travel time for missiles is too short. They might be warned, but they might not. Let's suppose that they don't respond in time, and Israel is destroyed while Iran remains intact. Is the United States necessarily going to strike Iran with nuclear weapons? There would be a significant body of opinion in the U.S. against such an action. Remember, Israel is already gone; that can't be made good. Would you want to blow up 70 million Iranians just as revenge? Of course you would want to take out the government, but you don't need to destroy the whole country to accomplish that. And while the people of Iran have certainly been complicit in the establishment of a wacko regime, they haven't all been complicit -- certainly not the children.
So I don't think a decision to retaliate against Iran would be taken lightly. The president, even a Democratic president, would probably respond quickly and forcefully, but not necessarily with nukes. The same applies to a prospective North Korean attack on South Korea or Japan. Suppose North Korea just sent one missile, destroying Seoul or Tokyo? Would we retaliate by blowing up Pyongyang, or would we flatten the whole country? And how long would it take us to deploy the missiles or bombers to undertake the attack? If North Korea retained a portion of its nuclear arsenal, it might well threaten to use the rest if we retaliated. What if your choice was let Seoul go unavenged, or to consent to the total destruction of both Koreas? That's not a simple matter -- both answers are bad.
I fear, therefore, that nuclear weapons are going to be used, if not in the immediate future, then in my lifetime. Actually, I have felt this way for a long time. If nuclear weapons technology exists, someone will build nuclear weapons; and if the weapons exist, eventually someone is going to use them, MAD or not. I don't have any solution for this, as I have no confidence in disarmament (see proposition 1). The United States can protect itself to some extent by building a missile defense, but this is much less of an option for neighbouring countries such as Pakistan and India. There is also the possibility of the use of tactical nuclear weapons -- nuclear-armed artillery shells, for example -- or of small bombs delivered by terrorist attacks. I have no comforting conclusion, only to report that, given my analysis, I support the destruction of nuclear weapons in any countries small enough for us to destroy them, whether by covert activity, airstrikes, or even ground invasions. Israel has kept Iraq and Iran from joining the nuclear club for a long time now, and I think we owe them a great thanks for that. I also think we ought to assist them by every means possible to keep it that way. North Korea is trickier, because of the problem of Chinese protection. (Fortunately, nuclear powers Russia, China, and India all have Muslim minorities that make them as concerned about Islamic terrorism as we are.) The best option is for Japan to rearm aggressively, especially its airforce and navy (it has no need of a large army at this point), and be prepared to respond to North Korea's aggression on its own or in conjunction with the United States.