Doesn't Ukrane have quite a few nukes, too?  (Old Russian ones.)
According to wikipedia most were returned to Russia, but they are suspected to have a few hundred that are not operational.
Ukraine - signed the Nuclear Non-Proliferation Treaty. Ukraine inherited about 5,000 nuclear weapons when it became independent from the USSR in 1991, making its nuclear arsenal the third-largest in the world. It transferred all of these to Russia by 1996. However recent news has surfaced that due to a clerical error, Ukraine may still possess several hundred warheads which were not accounted for in the armaments repatriation move 14 years ago. In any case, even if Ukraine does possess these weapons, they are technically missing and not in a deployed state or any part of Ukraine's defense posture.

Or at least, that's the offical story...

it's a sad world where Wikipedia (that bastion of accountability and oversight) gets called "the official story"...
I'll go out on a limb and just say that 99% of the time I find Wikipedia to be a good first source of information. Of course it has it's issues, but so does every information source.
as you said it's a "good first source", if you know next to nothing about the topic.  but to call it the "official story" is rather naive, given it's poor handling of many controversial subjects (e.g. depleted uranium, Central Banking and The Fed, nature of corporations).  why should i trust it to tell me where the Ukrainian nukes are?  there is no accountability (at least there is someone to blame for corporate-fed reporting in NYT, WSJ, etc.) and any person can write whatever is "acceptable" to the amorphous "editors" of Wiki.  i have found quite a bit of selective source inclusion/exclusion going on over there and uncited use of government propaganda.  
isaiah, I understand all that, but based on all else I found, Wiki was the best summarized and most succinct abstract on this very specific topic. And when I said "official story", I meant that there was probably much more to this issue (e.g. I bet the Ukrainians have a small nuclear deterrant), but without any other information to the contrary that has to be the story until more facts emerge. I invite you and others to explore this topic and research it in more depth.