I've heard this argument before but I don't really buy it. I don't think Bush was even seriously considering WMDs or denuclearization when he crafted his foreign policy (obviously they knew enough to lie about them, but there's no indication internally that Bush and his people gave that a priority when crafting foreign policy). Like Iraq, Libya's WMDs were old chemical weapons from the 1980s and the Bush Administration only sought to "disarm" them as cover for when it became abundantly clear to the public that the UN inspectors were right - that Iraq had no WMDs.
As for the other three, nuclear armament has been a crucial part of North Korean foreign policy for over 50 years now. Although I agree that Bush blew up the only chance at stalling or scrapping the North Korean nuclear program, which would have been the normalization of relations. I don't think anyone would actually want to go to war with India or Pakistan. Ignoring the millions of lives lost in any conflict of that nature, it would be a massive and pointless exercise in creative destruction.
The real truth of international nuclear policy is bleak. Nuclear weapons are a guarantee that a country will not be invaded, or at least that they'd be taken seriously on the global stage. In hindsight, Ukraine was foolish to give theirs up. And, US policy in this theater is always going to be flawed or seriously lacking until they take steps to denuclearize on their own as well.