I've seen a few things arguing that these events, particularly the thing about the Budapest Memorandum, mean that nuclear disarmament and non-proliferation are now things of the past.
Every country that wishes to have a nuclear weapons program can now point at Ukraine and say that that is what happens when a country gives up nuclear weapons.
so now Saudi Arabia's off-the-shelf weapons from Pakistan, and Iran's self-built ones cannot now be opposed by UK or US diplomats.
Nuclear non-proliferation and disarmament are fundamentally based on the big 5 - US, Russia, China, UK, and France - not violating/threatening the sovereignty of other nations.
Iraq (2003), Georgia (2008), and Senkaku Islands (2013) all drive their neighbors (or world) to consider nuclear weapons as a deterrent against superpower or even regional power aggression.
In 1991, Saddam (incorrectly) believed his WMD arsenal dissuaded the US-led coalition from turning from the liberation of Kuwait to the conquering of Baghdad.
Despite Israeli concerns, I am pretty sure Iran wants nuclear weapons to act as a deterrent against the US/West. Saudi Arabia wants nuclear weapons to as a deterrent against Iran.
Japan wants nuclear weapons to act as deterrent against China.
Until such a time as the delivery of nuclear weapons is far from assured (Anti-Ballistic Missile systems* and sophisticated Air Defense Systems), then it makes sense in terms of realpolitik for the second tier powers to pursue the development and fielding of nuclear weapons. It causes first tier powers to consider their actions more carefully. An invasion of a nation without even basic ICBMs and nuclear warheads allows the global power to dictate the geographical confines of the conflict, but the moment Washington, Moscow, Beijing, London, Paris (or other metros) can be obliterated from a far, the global powers have to rely on the rest of the power tool kit, which can be hard to wield.
*Three nations heavily invest in this technology - US, Japan, Israel. It also gets
Russia all bent out of shape when ABM systems are deployed near their borders.