One thing that has been mentioned but seldom actually discussed during the Crimean crisis is the fact that 20 years ago, Ukraine hosted the third largest stockpile of strategic nuclear weapons, next only to Russia and the USA. As has been stated a number of times by different media, they transferred their warheads (and some carriers) back to Russia for dismantling, and in exchange received written promises that Russia would “respect the Independence and Sovereignty and the existing borders of Ukraine [and] to refrain from economic coercion designed to subordinate to their own interest the exercise by Ukraine of the rights inherent in its sovereignty and thus to secure advantages of any kind.”
The problem here is that the obvious lesson seems to be that being nice doesn’t work in the real world.
It is difficult to say whether keeping a nuclear stockpile would have worked as a deterrent against the Russian invasion of Crimea, and if Ukraine would have met the economic and technical requirements to maintain such a deterrent. However, what we do know is that the written assurances did not work, so it is no far-fetched guess that in Ukraine today at least some of its leaders asks themselves if it was a mistake.
I don’t believe Ukraine will ditch the NPT to develop a new arsenal due to a number of reasons, not the least of which is how Russia would react to such a decision. However, there are a number of places in the world where this might have implications.
That nuclear weapons are restricted to certain countries is not a law of nature. In fact, quite a number of countries studied whether or not they should acquire their own weapons in the early part of the Cold War, but in the end, the costs and technical difficulties meant that only a handful of countries actually created operational weapons, and in the meantime nuclear weapons had received a fairly bad reputation amongst civilians, something which further restricted their use. However, this is in no way an irreversible process, as e.g. North Korea has shown.
If it is felt that the NPT does not work, countries that feels threatened by their neighbors (especially if the neighbors are armed with WMD’s), might very well start to look into the possibility of acquiring their own. Especially in the Far East, where China has both a sizeable nuclear stockpile and is starting to flex its muscles more aggressively, countries such as Japan, South Korea and Taiwan/ROC may feel that the added security of a nuclear shield is worth the worsening diplomatic relation such a move would create. This will not happen in the near future, but I believe it is not impossible in the medium term. Japan is struggling with worsening demographics and an uncertain economy which might hamper its planned expansion of its conventional forces. South Korea has the latest nuclear state as its neighbor and is quarrelling with China about its sea borders. Taiwan is always looking for ways to stop a Chinese assault, and while China rapidly is expanding the PLAN, the US is a far from certain ally. In all cases, having a nuclear deterrent might be just the solution the politicians are looking for.
And Ukraine being invaded by the country it gave its weapons too, might be just the spark needed for a new nuclear arms race to start.
Edit: Over at KKRVA a nice analysis partly about the same subject can be found in Swedish under the title Ukraina – Tre döende patienter.