Pakistan's army chief General Ashfaq Pervez Kayani has warned Washington to "think 10 times" before launching any unilateral offensive in the restive North Waziristan tribal region even as an angry and frustrated US is lining up its artillery on the Afghan border facing Pakistan. The Obama administration is also initiating fresh diplomatic efforts to persuade Pakistan to reel back its "self-destructive" policy of seeking strategic depth through terrorism before more aggressive military action. US secretary of state Hillary Clinton is heading for Islamabad this weekend in a trip that is officially secret but is being discussed animatedly in diplomatic circles...