Such dismissal can make deterrence almost useless. The question, as many have pointed out, is not how many missiles or bombs the United States has but the perception, abroad, of how willing the United States is to use them. It would be a tragedy of the greatest magnitude if millions of Americans, followed by millions of, say, Chinese or Iranians, were to die because of a misperception. When the Chinese read about U.S. attempts to erect a national missile defense, they are seeing the intimidation value of their nuclear forces begin to evaporate. Despite many claims and continuing efforts, the Chinese seem unable at this time to build and maintain the sort of modern nonnuclear forces which would be needed to overrun Taiwan and other targets of interest.
Nuclear weapons are a cheap way out, but only as long as they are taken seriously.
It is no great surprise that the Chinese have greeted the U.S. NMD program with deep anger. Despite worrisome proliferation trends, no Third World governments appear likely to be able to afford massive long-range missile forces. Their budgets are limited. Their expectation is that even a very few missiles capable of reaching the United States will offer enormous leverage. It follows that, to destroy that leverage, relatively small numbers of interceptors may well suffice.