I somehow don't think Ukraine would be threatening us with first use of nuclear weapons even if they have them. They are not our enemy.
But regardless of whether they would or would not even if they did have them, the fact that they don't have them doesn't change the validity of the argument. Russia is threatening first use of nuclear weapons, and Ukraine is not. And by threatening first use of nuclear weapons for the sole purpose of conquering territory in a neighboring country, Russia has crossed the line that neither the United States nor the Soviet Union ever crossed during the entirety of the Cold War.
So for those who claim that us unrepentant cold warriors have refused to recognize that Russia is not the Soviet Union, and therefore not a threat, Russia has just proven the opposite to be true. It is actually worse than the Soviets were.
We owe UKR NOTHING, period, and they are not the friend of the US. They are a friend only to themselves and their own devices. Zelensky is just as big a madman as Putin, but at least Putin has some kind of oversight. T-shirt Zelensky is just a dangerous loose cannon.