Yes, Zia too, just like Bhutto, tried to use Islam as a political tool and he enacted few of the most controversial laws in the country but he didn't
accelerate anything. 'The irreversible damage' had already been done by ZAB
It was during Bhutto's regime that religion became the official legitimizing strategy for all political manoeuvres. In a frenzy to break the momentum of the PNA-led movement, numerous Islamisation measures erupted. Shariat laws were introduced; gambling, horse racing, and alcohol were banned. The PPP manifesto was duly amended, making Friday the weekly holiday, introducing Quranic studies as mandatory for all students, establishing Ulema (clerical) academies and so forth . These moves established the PPP’s dedication to the cause of Islam, which became Bhutto’s most powerful defence to fight the PNA in their own battlefield.
He was the one who made Islam the state religion and set pre-requisites for the head of state to be Muslim.... One of Bhutto’s last desperate bids to buy off religious parties agitating for his overthrow with U.S. backing was to declare the Ahmadiyya Community non-Muslim in 1974 ... The concept of "constitutional kafir" was introduced for the first time, thereby making "official adoption" of sectarianism (as a state policy)...
In 1976, ZAB controversially appointed General Zia-ul-Haq the Chief of Army Staff in another move to appease the JI (of whom Zia was a close compatriot) ... Zia ul Haq was the Pakistan army's most junior Lt. General when Bhutto selected him to be Chief of the Army Staff.... Later regretting his choice, ZAB told the Supreme Court (which sent him to the gallows): "I appointed a Chief of Army belonging to Jamaat-i-Islami and the result is before us." ... Bhutto institutionalized mullahism through the constitution, and then he appointed an Army Chief belonging to JI .. !! Who is the 'actual' culprit behind the "damage" then ?? Zia, or the "politician" Zulfiqar Ali Bhutto?
You can't have it both ways, dear
You are 'assuming' that Bhutto would have continued the Nuclear programme but he would NOT have continued with the Islamization drive... Bhutto may very well have
continued with the religious drive and rolled back Pakistan's nuclear program... 'Assumptions' don't matter ... If you are unwilling to give credit to Zia for the successful completion of Pakistan's nuclear program, you cannot blame him for the Islamization of Pakistan either. Simple as that
Even today, Musharraf's four-point formula on Kashmir offers the best possible solution.