ISLAMABAD is now more like a revolving door through which American officials walk in to monitor how effectively the Pakistan Army is combating terrorism. Richard Holbrooke left and in comes CENTCOM Chief General David Petraeus. Soon after arrival here from Tashkent, Gen Petraeus held a meeting with COAS General Ashfaq Parvez Kayani at the latter's office on Wednesday and discussed with him the war on terror, the security situation of Pak-Afghan border area and ways to enhance defence cooperation between the two countries. News reports quoted diplomatic sources as saying that the visit was aimed at expediting the delivery of weapons and intelligence equipment to Pakistan so that it could expand its offensive against militants in the tribal areas bordering Pakistan. During his stay here he is also expected to meet the country's top political leadership. Americans must be told that while Pakistan is prepared to bolster intelligence sharing between the two armies it could not allow their troops to carry out any operation on its soil.