Following the failed Times Square car bombing, the Obama administration is urging Pakistan to move swiftly against the militant Islamic hub in the country’s lawless tribal regions. General Stanley McChrystal met with a Pakistani military chief Friday to discuss a military offensive against the Pakistani Taliban and al Qaeda in North Waziristan, the area where the alleged Times Square bomber, Faisal Shahzad, reportedly trained. Both the Pakistani and American sides characterized the new pressure as a departure from the polite encouragement adopted by the Obama administration. Although Shahzad failed to detonate the bomb, his ability to move back and forth between the U.S. and Pakistan worries Washington officials that another terrorist attack could be in the works. The issue of a greater U.S. presence in Pakistan is a source of growing tension between the countries, although American officials say if there is a successful attack on U.S. soil from a Pakistani terrorist, the U.S. military will have no choice but to act.