President Asif Ali Zardari has called for doing away with the extremist thinking, and added that 'no foreign power could harm us if we have unity in our ranks. Addressing the tribal elders in Peshawar on Tuesday, Zardari deplored that the refugees who were given asylum some 30 year back 'stabbed in our backs and killed Benazir Bhutto. Zardari urged harmony, and called upon them to support the government to get its support. He assured that everybody would be taken on board regarding the FATA amendments.