there is literally nothing Pakistan can do to stop India from building dams. Even if it goes to ICJ India doesn't adhere its ruling ( read about past icj rullings on India). You try to bomb the infrastructure India with blow yours. And Pakistan will never go nuclear in a war it started on its own, because it cannot survive the aftermath
Read this you'll get an idea what will happen after the icj ruling even if it favors Pakistan
Has India ever taken as case to the ICJ?
Yes, once — even though it has been a party to a total five cases, three of them with Pakistan, at the ICJ. In 1971, India filed a case against the jurisdiction of International Civil Aviation Organisation (ICAO) to decide on Pakistan’s demand that India could not deny it overflight and landing rights. India had withdrawn Pakistan’s overflight rights after the January 1971 hijacking of an Indian Airlines flight to Lahore, and the gutting of the aircraft by the hijackers. The ICJ ruled against India, saying that ICAO had jurisdiction in this case.
In 1954, Portugal had filed a case against India over denial of passage to what were then the Portugese territories of Dadra and Nagar Haveli. ICJ decided in India’s favour in 1960, saying India’s refusal of passage was covered by its power of regulation and control of the right of passage of Portugal.
In 1973, Pakistan filed a case to stop the repatriation to Bangladesh of 195 Pakistani nationals in Indian custody after the 1971 War, to face trial on charges of genocide, but withdrew the case the next year. After 1974, Pakistan, a Commonwealth nation, can no longer take India to the ICJ.
What has the government said now?
Earlier this week, External Affairs Minister Sushma Swaraj said that if the Supreme Court gave permission, the government would approach the ICJ. “The Centre will be requesting the Supreme Court to pronounce a verdict on the legality of the stand, taking into account the exceptional circumstances. The Centre will be open to invoking the jurisdiction of the ICJ,” the MEA spokesperson added.
What does this position imply?
It is India’s own law, ratified by Parliament, which denies the ICJ jurisdiction over this matter. Even if the Supreme Court asks the government to move the ICJ, it is highly unlikely that Pakistan will accept the Court’s jurisdiction in this case. Also, going to the ICJ can theoretically open up all cases between India and Pakistan to multilateral jurisdiction, thus weakening New Delhi’s consistent stand that all issues with Islamabad would be resolved bilaterally. Once India has accepted ICJ’s jurisdiction over bilateral issues, Pakistan could well demand that the ICJ arbitrate on alleged human rights violations in Jammu and Kashmir, or military operations on the Line of Control, or any other issue.
This was the main reason India didn't appose China ignoring icj ruling in SCS officially,which China bragged it had Indian support