I can agree on many issues regarding the Iraq war, I think we all heard about the "weapons of mass destruction" that turned out to be false (well, never proven at least). It wasn't the only reason, though [1]. A very important quote from there:
> UN Secretary-General Kofi Annan described the war as illegal, saying in a September 2004 interview that it was "not in conformity with the Security Council"
However, I find comparing Ukraine to Iraq simply unconvincing. The latter had a recent history of aggression [2], which largely fueled the suspicion about the "weapons of mass destruction".
Comparing saddam husein [3] to Volodymyr Zelenskyy also fails spectacularly.
The comparison to the Cuban Missile Crisis is a miss too: in Ukraine the opposite happened, the nuclear weaponry was removed which was the Ukraine's part of the Budapest Memorandum on Security Assurances [4]. However russia doesn't respect its part:
> 1. The Russian Federation [...] respect the independence and sovereignty and the existing borders of Ukraine.
That's why I call it symmetrism: on one side there's an aggressive country, run by a tyrant with proven crimes against humanity, on the other a democratic country that wants to be free and independent and choose its allies. But putin considers it aggression.
It's one thing if it's a valid casus belli - people thinking so I consider to be unreasonable.
Another thing is, that putin calls a lot of things an aggression against russia. Recently he called sanctions such aggression. So now pretty much the entire world, in this madman's mind, has attacked russia and *IF* we accept the casus belli used against Ukraine, we have to accept a cassus belli against any other country putin attacks next. In other words, the idea behind cassus belli corrupted to the point where it's useless. It's like defining "cold" as colder that a quadrillion °C - now everything is cold, even the center of the Sun. The word became useless.
[1] https://en.wikipedia.org/wiki/Rationale_for_the_Iraq_War
[2] https://en.wikipedia.org/wiki/Invasion_of_Kuwait
[3] https://en.wikipedia.org/wiki/Trial_of_Saddam_Hussein
[4] https://en.wikipedia.org/wiki/Budapest_Memorandum_on_Securit...