Basically, what the State Department did in 1981 is similar to what they are doing now with Iran
http://travel.state.gov/travel/cis_pa_tw/cis/cis_1142.html
So, where is your evidence to the contrary? You cannot make a blanket statement like yours without a reference.
LOL! You're the one making these absurd claims! *YOU* back them up with evidence! That's how these things work.
Please, a link to an official source (not someone's blog) detailing how Pakistan was off-limits to Americans in 1981 would be fine.
Claiming that because "Pakistan was under Martial Law so it was unlikely they would have granted visas" is nothing more than making stuff up and hoping it sticks. And the Iran link provides no evidence either.