America never had any intentions of helping Pakistan develop, it was only ever giving a piece of candy to achieve its regional strategic objectives.
All about your priorities as a nation
If you
want to devalop - You
WILL devalop
But since 90s and to some extent 80s we got too sucked into Afghanistan- that consumed our country, I'll be honest
Than 90s political bickering
2000s some semblance of economic growth but got sucked into waziristan and soft insurgency in Balochistan
Somewhere after the 80s we have lost focus as a country - Bhutto had a plan (bad or not there was a plan- nationalization was an economic plan , crap one but a plan)
Zia had no economic plan but a geopolitical plan
By the 90s there's no economic or geopolitical plan- it's just going without a direction
For civllian leadership you have zardari and Sharif
Who are locked in a constant power struggle between themselves and the millitary
Millitary is interested in controlling the country but is not interested in a coup like back in the day
Cause this Pakistan is 180 degree different from the old pakistan and it won't be tolerated
This lack of control is leading to lack of direction leading to slow deterioration since the 90s
To end this someone needs to be given control to steer the ship
This "behind the scenes" thing isn't working nor is this frickle parliamentary democracy
(I believe in no millitary direct or indirect involvement in anything, that era is gone for good (indirect still ongoing), I strongly believe in democracy for a multi ethnic country but presidential system with decentralized Powers not parliementry democracy)
They still see Pakistan as a radical Islamic country with nukes, and a potential problem in the future. They've tamed the country and that's why the nuclear weapons rhetoric had calmed down.