For months, Bush administration officials have talked about the threat of a smallpox attack but have offered no strong proof. But by asking millions of Americans to accept the risks of smallpox vaccinations, President Bush has signaled that he thinks the possibility of an attack is rising as the United States considers a war against Iraq and assesses long-term dangers. |
Experts on risk assessment say a short-term danger grows as time passes. For example, a coin flipped has only a 50-50 chance of coming up heads, but flipped many times will eventually land heads up. |