Ukraine now regrets giving up their nuclear weapons.
The "red line" of Ukraine attacking either Crimea or internationally recognized Russia was crossed and revealed to be a bluff.
The wall against proliferation will eventually break. For the life of me I can't figure out how Iran had a much harder time refining U235 with centrifuges than Pakistan did in the 1970s; I mean, I can understand how the US has been unable to deploy centrifuges to make enriched uranium for reactors (the same reason we can't have so many other nice things) but why Iran?
The lesson of Gaza may be that a people in a similar situation might want to have nuclear weapons at all costs. There definitely are paths left out of the conventional analysis of proliferation paths (accelerator-based methods, AVLIS) and even though they could reduce the footprint of producing the fuel they are also all super-high tech.)