Az Ukrán SzSzK a Szovjetunió része volt, így a szovjet atomfegyverek azon része, amik Ukrajna területén voltak a Szovjetunió felbomlása és Ukrajna létrejötte után, azok Ukrajna tulajdonába kerültek, ezért tudott lemondani róluk.
"A Szovjetunió de facto és de jure is megszűnik létezni. Jogutód a nemzetközi szervezetekben, a külképviseletekben az Orosz Köztársaság."
Nem kerültek ukrán tulajdonba: sőt nem túl meglepő módon a kezelőik is elsősorban orosz csapatok voltak.
Ajánlott olvasmány:
https://www.hks.harvard.edu/publications/what-happened-soviet-superpowe…
[..] Had Ukraine retained the strategic nuclear weapons it inherited from the former Soviet
Union, it would instantly have become the third largest nuclear weapons power in the
world. The implications of this fact for U.S. national security can hardly be exaggerated.
Some 1,250 nuclear warheads on ICBMs targeting American cities would have come
under the command of a new and unstable government in Kiev.
In one of its first and most consequential national security initiatives, the Clinton
administration moved in 1993 to engage Ukraine in a multi-dimensional relationship
aimed at ensuring prompt and complete denuclearization. [..]
Továbbá
https://www.armscontrol.org/act/2014-12/features/looking-back-ukraines-…
[..]Ukraine’s claim to nuclear ownership was not entirely untenable; its legal succession to the Soviet Union was recognized in relation to conventional armed forces.[41] If successful, however, the claim would have dragged out the country’s denuclearization indefinitely, with profound repercussions for the entire post-Cold War settlement. It ultimately collided with the interests of Ukraine’s powerful interlocutors and the precepts of the international nonproliferation regime. The very existence of the NPT meant that a different set of rules applied to the nuclear part of Ukraine’s military inheritance than to the conventional one. Furthermore, the NPT’s stark binary categories of “nuclear-weapon state” and “non-nuclear-weapon state” could not be reconciled with Ukraine’s new category of “nuclear ownership”—legal possession without operational control—which fell somewhere in the middle. Ukraine could sustain its claim only by remaining outside of the NPT. That option would have spelled isolation from the international community, which Ukraine ultimately wanted to join, not defy.[..]