That is simply not the case. First, Obama traveled to Pakistan in 1981, not 1978. Second, I traveled to Pakistan during the period 1979 to 1981 multiple times, albeit using my diplomatic passport.
However, I can say there was no problem in getting visas to go to Pakistan for Americans. There was a travel advisory warning of possible terrorist attacks, but there was no prohibition for Americans to travel there nor did the Government of Pakistan stop issuing visas to Americans. I met many Americans during my trips to Pakistan including school teachers, businessmen, etc.
Ref post #23.
Thank you for that information.