In the wake of the defeat of al-Qaeda and the Taliban at Tora Bora, Afghanistan, many of them flee into the tribal region of Waziristan, just across the Pakistani border (see December 2001-Spring 2002). These tribal regions normally have no Pakistani military presence, and the Pakistani army left the border near Waziristan unguarded (see December 10, 2001). [Rashid, 2008, pp. 148, 268] In early May, the US begins applying pressure on Pakistan to act. On anonymous Defense Department official tells the Washington Post, “We know where there is a large concentration of al-Qaeda.” He notes there are several hundred in one Waziristan border town alone. A senior US offical says, “We are trying to encourage, wheedle, coerce, urge the Pakistanis to move more aggressively” against the Waziristan safe haven, but have not been having much progress. [Washington Post, 5/12/2002] Pakistan finally moves army units into Waziristan in late May 2002, but even then the 8,000 troops remain in the administrative capital of Wana and do not attempt to seal the border with Afghanistan. [Rashid, 2008, pp. 148, 268]