Over the past half century, weapons of mass destruction have presented mankind with a challenge never before witnessed in our history. One nation can now obliterate another within minutes, courtesy of a technology that sets a new threshold for wide-scale devastation.
During the Cold War, the United States was able to point nuclear missiles toward Soviet Russia, the heart of the evil empire, and the U.S.S.R. targeted us in return. Because there was an explicit understanding on both sides that the use of such weapons would result in our mutual destruction, both sides were provided with a deterrent — and with some degree of security.
It is obviously the moral obligation of a nation to protect itself from its adversaries.
Therefore, according to the religious obligation of self-preservation, it was (and is) acceptable to employ nuclear weapons as a defensive tactic. Unfortunately, the "good old days" of the Cold War are over — now we are challenged by the far more reckless and sinister enemy of Islamic extremism, to which the notion of mutual assured destruction means nothing.