Writing at The Globe and Mail, Lubomyr Luciuk remembers when Ukraine voluntarily gave up its nuclear weapons in exchange for "territorial integrity" guarantees from NATO... and Russia:
I recall what I wrote just before Ukraine re-emerged as an independent state in Europe, when the USSR disintegrated, in 1991. My views appeared in this very newspaper, Nov. 15, 1991, "Moderation and neutrality — but hang on to the nuclear arms." I argued Ukraine's independence would be compromised, perhaps fatally, if Kiev gave up its nuclear arsenal, unless the West guaranteed the country's independence and territorial integrity. The West gave exactly that guarantee. So did the Russian Federation. Ukraine then disarmed, the only country in the world to have ever given up its nuclear weapons, even as other states scrambled to acquire them.
Today we know Moscow's promises are valueless. We shall soon learn what NATO's guarantees are worth. [The Globe and Mail]
Now, most experts say that NATO is not obligated to protect Ukraine, which is not a member state, after all. (In the agreement Luciuk cites, NATO vows to respect Ukraine's sovereignty, i.e. not to invade it, but only promises that its member states will "consult together" if the country is threatened.) Yet this could still have ramifications for non-proliferation efforts.
The illogic of mutually assured destruction aside, nations truly believe that nuclear weapons offer them a safeguard against attack. Ukraine's predicament isn't going to convince them otherwise.
Read Luciuk's full article, which includes more details about the agreement, here.