Want to know their logic? They don’t consider Pakistanis as muslims, so that makes it ok to kill Pakistanis. Read the account of David Rhode of his captivity in Miran Shah, North Waziristan.
“In March, they celebrated a suicide attack in a mosque in the Pakistani town of Jamrud that killed as many as 50 worshipers as they prayed to God. Those living under Pakistan’s apostate government, they said, deserved it.”
http://www.nytimes.com/2009/10/20/world/asia/20hostage.html?pagewanted=3&_r=1
"I tried to get to know one of the guards, who was preparing to be a suicide bomber. A young man in his 20s with a slim build and brown eyes, he said he had studied engineering in high school. He never attended college but was relatively well educated compared with the other fighters.
When I asked him why he wanted to die, he replied that living in this world was a burden for any true Muslim. Heaven was his goal, he said. Earthly relationships with his parents and siblings did not matter. "