Missed Opportunity
There was a short time under the Clinton administration when Russia was friendly with the United States under Boris Yeltsin, and China's sole nuclear-armed submarine was in port for repairs. But we missed the opportunity for a pre-emptive strike followed by regime change in China. Then, with the threat from China eliminated, Russia and India could have given up nuclear weapons - and Pakistan would no longer need them to keep up with India. The world would have been saved from the threat of nuclear war, with all nuclear weapons in the hands of responsible countries - the United States, Britain, and France - and there would no longer have been any threat against Taiwan.