The said report also clearly States that the third planned attack on Karachi was thwarted after Pakistan Navy counter attacked which resulted in the sinking of an Indian warship....... after that no attacks were executed on Karachi ........
now if Karachi was neutralized altogether then why the third attack was planned???
if karachi was left inoperable, then why the Pakistan Navy clearly outnumbered bothered to counter attack???
as I said before,
given the presence of resources.... Karachi was adequately defended....... unfortunately it happened later then it should have.
US being able to blockade is another conversation better left non-discussed.
There was no need to execute any attack on Karachi because Karachi was not operational. Read the CIA report I have linked to. That is a neutral source. Your source is Pakistani.