The numbers are part of a nationwide trend of rising violence. In the southern and southeastern provinces, including the insurgent hotbeds of Kandahar and Helmand, guerrilla attacks spiked by 40 percent, according to Mr. Kovanen's research.
Kabul itself has been largely free from the violence, but as Sunday's attack shows, there are signs that the Taliban's presence is growing here, too. On the sprawling, serene campus of Kabul University, where the nation sends many of its best and brightest, the Taliban has reached an unprecedented level of influence, students say.
Young men gather in campus dorm rooms and watch slickly produced DVDs of the latest insurgent attacks. One video shows Taliban fighters firing rocket launchers and shrieking, "God is the greatest!" as orange fireballs reach their targets, presumably Coalition forces, in the distance. The attacks are set to religious music, backed by a staccato drumbeat meant to impassion and inspire viewers.
"Many of us have contact with Taliban leadership," says one student and Taliban member, who asked to be called Naqibullah. "I talk to commanders based in the south maybe once a week on the phone." Naqibullah and others like him disseminate Taliban propaganda throughout the university, hoping especially to reach students from various parts of the country.
Naqibullah suggests that places like Kabul University might be a fertile recruiting ground for operations in the capital and in northern areas of the country. "There are many students waiting to launch suicide attacks," he says. "One student launched a suicide attack in Bagram," an American base north of the capital.