But yesterday's blasts show that some suicide bombers continue to get through the security mesh. The developing problem, Western officials say, is the Taliban tactic of "random" suicide bombings, in which would-be attackers drive or walk through the city waiting until they spot security flaws and high-profile targets.
Security sources say they believe the Jan. 14 commando-style assault on Kabul's Serena Hotel that killed seven was one such attack of opportunity. They believe the gunmen and suicide bombers did not necessarily plan to hit the hotel on that day, at that hour. Instead, they were dropped in the neighborhood, armed, and chose to strike the Serena when they spotted a perceived weakness in the hotel's security.
The Taliban subsequently vowed to hit restaurants and other places in Kabul where members of the international community tend to gather after work, a threat that has led most foreigners to adopt a much lower profile.
