We joke about aircraft carriers today, but pre-1971, it was worth real consideration. Back then, the PN had to maintain two distant trading centres (Karachi and Chittagong) and two major sea trade links. In fact, time had shown that both sides were massively important (the Arabian Sea and East Asia).
Bar external reluctance and/or foul play, there was no excuse for Pre-1971 PN to not get an aircraft carrier when Argentina and Brazil could get one. Ironically, the PAF's first jet was originally a carrier-borne design (Supermarine Attacker). Imagine, if we had looped those jets to the PN with one of the RN's surplus carriers...
That said, I'm not giving Ayub Khan as much flack because, at that time, Pakistan-US relations were really good. Our defence planners genuinely thought the US would have our back provided we don't do anything out of order. Unfortunately, ZAB convinced us to do something out of order, and the rest is history.
We can credit ZAB for giving us nukes (though the technical base was all established before his time), but if not for this guy's existence, we likely wouldn't have needed them. It went downhill from 1965.
@SQ8