Charles Krauthammer suggested that President Obama's shift in retaliatory nuclear policy endangers the United States by removing nuclear weaponry from our menu of responses to an attack from abroad ["Nuclear posturing, Obama-style," op-ed, April 9]. But he sees the issue anachronistically, missing the evolution that conflict has taken in the past few decades.
The Cold War is over, and the world has changed; the United States is no longer seen as the antithesis to a growing totalitarian empire. Deterrence made sense when our enemy, the Soviet Union, threatened the whole of Eastern Europe.
Now, however, we are fighting enemies that enjoy a certain underdog popularity, and we must tread lightly or risk validating their claims against us. Our attacks, if they come, will come from nonstate actors based among civilian populations; will we, as Mr. Krauthammer suggests, leave Islamabad or Kabul "a cinder and a memory"? What of hearts and minds then?
A supporter of mutually assured destruction, the old nuclear deterrent scheme, would note that its strength resides in its threat, not in its use. But how much does a threat undermine our authority if it's a threat we could never realistically fulfill?
Josh Raisher, Washington
We live in a world in which nuclear weapons are possible. It would be better if this were not so, but we must live in the world as it is, not as we wish it were. The materials to make nuclear weapons occur in nature; you just dig uranium out of the ground. The knowledge of how to make such weapons is out there and can never be recalled.
The Manhattan Project went from raw uranium ore and first principles of physics to an operational nuclear weapon in three years, using predominantly 1930s technology.
A modern industrial nation could become a nuclear power in weeks. From the earliest days of nuclear research, it was understood that there is no defense against such weapons. The only course is to deter attack through a credible threat of retaliation in kind. Awful as this is, it has kept the nuclear peace for 65 years.
We can't wish away nuclear weapons. We must continue to live responsibly in a nuclear world, not engage in meaningless feel-good gestures that make a nuclear explosion in a major city more likely, not less.
Michael White, Sterling