A strong message. But was the follow-through strong enough
You will either let the US  fully inspect all of Pakistan’s nuclear facilities (covertly, of course),  establish a permanent monitoring regime of them (also covertly, of course), as well as  personally purge all militant-Islamist-sympathasizers from the ranks of those parts of your scientific/military/intelligence establishment responsible for the nuclear program (we’ll leave the level of discreetness and brutality up to you on this one, Pervez) or you will find the US shall stand aside as India goes to war with Pakistan*, Pakistan inevitably loses the conventional war, and events then in all probability escalate into a nuclear exchange. By the way, if we stand aside and somehow peace and reason prevails and India doesn’t start a war with you, please note that the US has never renounced the option of conducting a first strike with nuclear weapons. [Too Many Worlds]
It may take another thirty years before what really transpired becomes public, but facts on the ground reveal that the American ultimatum did not entirely have the desired effect. Pakistan was using US supplied C-130s to carry out ‘missile for fissile’ barter transactions with North Korea in 2002 and selling weapons technology to Libya as late as 2003. Purists may quibble about how Khan’s proliferation is a shade different from Pakistan’s operational nukes (which is what Friedman is talking about); but that means the US was guarding the door while keeping those huge french windows unlocked.