That's not to say that the cruise ship and military incidents are definitely terrorism, but it is a mistake, in this day and age, to immediately try to explain it away. We can't afford to assume the hypothesis that these incidents have a benign cause. THAT is likely why President Bush is ordering the Smallpox vaccines for troops. He has the burden of making that decision you described, and unlike his predecessor, he is erring on the side of caution.
I agree, a very big and foolish mistake to do so. Anticipate/plan for the worst (terrorism), hope for the best (naturally occurring/coincidence). Err on the side of caution...best thing to do. Yes, this means everyone will have to "deal with it," from the CDC on down to the little guy on the street. But, really, what "sound" alternative is there? We risk our lives and health otherwise. Peace of mind can come in taking precautions, too. Why, that's what folks live by in California as pertains to earthquakes. When I lived there, the schools (and other public entities) were constantly driving it into the parents (via the kids) to have clean, unused huge garbage cans filled with emergency supplies (blankets, water, first aid kits, food supplies for four days, enough for each person in family, batteries, portable radio, flashlights, etc., in anticipation of a major earthquake). This did not mean people lived in fear everyday, that their lives were "jeopardized" or "traumatized" by being urged to "be ready." It just equipped them for what is perceived a "high inevitability." What is wrong with this approach as pertains to terrorists/terrorist activities? I say nothing.