> Give nukes to Ukraine, even pretend ones and war will end in minutes
This is the wrong answer. But it's clear non-proliferation has failed. If Ukraine had kept its nukes from the 90s, this wouldn't have happened. It would have had the ability to credibly threaten that it had reverse engineered the arming mechanisms.
> My understanding is that they were always in Russian control, kind of like how the US keeps nuclear assets at overseas bases
No. The 43rd Rocket Army "became part of the Armed Forces of Ukraine" on 6 December 1991 [1]. Unlike American warheads, which are on U.S. bases, those were Russian warheads on Ukrainian bases.
Not posting this as a definitive gotcha, but this article includes some detail on how the situation was "complex" at best
> In early 1994, after the Trilateral Agreement, "General Vitaly Radetskyi, Ukraine’s new Minister of Defence, summoned Mikhtyuk and two of his senior generals to Kyiv.[10] Without warning, General Radetskyi told them they had 15 minutes to decide whether to take Ukraine’s oath of allegiance. General Mikhtyuk and one general took the oath, while the other refused. Then, the minister ordered [Mikhtyuk] to return to his headquarters in Vinnytsia immediately, and convene all of his subordinate commanders. ..He did so explaining his personal decision to remain in Ukraine, and asking each officer to take or reject the oath. “All of my deputies,” Mikhtyuk recalled, “except one, said they would not take the oath and asked me to transfer them to the Russian Federation."
Of course it was complex. The point is if Kyiv refused to co-operate it would take Russian military strength it didn’t have at the time to seize them. That isn’t analogous to American nukes on overseas bases.
Give nukes to Ukraine, even pretend ones and war will end in minutes.