There was a news article about an interview discussing his contemplating entering military service around that time (remember USSR invaded Afghanistan in 1979 during Carter's presidency).
Also Pakistan is a country steeped in radicalism and was created out of Indian territory. Θbama visited because his room mates at Columbia were Pakistanis, but you notice he NEVER mentioned the Pakistan trip until around the time of the passport breach. He was spooked about an October surprise.
http://dailymusings.spaces.live.com/blog/cns!EBAB74DA8F94C559!5351.entry
“...Pakistan was in turmoil in 1981 and ruled of martial law. Millions of Afghan refugees were living in Pakistan, while the Afghan Mujahedeen operated from bases inside Pakistan in their war with the Soviets. One of the leaders that based his operation in Quetta, Pakistan was Usama Bin Laden (The Sheik).
Pakistan was on the banned travel list for US Citizens at the time and all non-Muslim visitors were not welcome unless sponsored by their embassy for official business...”