History

I think the context between the two was much different, so you can't say the two were the same at all.

In 2001, there was an attack on the twin towers in NYC and the pentagon, and one other target that we don't know (but it was probably the whitehouse). I remember waking up on September 11th 2001, after spending the night before reading about the DMCA and how Adobe had a guy who wrote a screen reader arrested for breaking rot13 encryption (basically just moving all the characters ahead by 13). So I woke up with my radio playing about some sort of attack, and I was like "heh, serves em right, assholes", but I turned out to eat my words seriously. What happened there wasn't justifiable (yeah yeah "well america did this, america did that" there's a discussion to be had about whether they were right, but nobody in those buildings did any of that, and neither did the people on those planes)

The 9/11 attacks weren't just some attack. It was a major tragedy for NYC, and Americans came together in a huge way. It's easy to forget now, but it was a pretty bipartisan thing at the time -- it was not acceptable to attack America. The immediate war in Afghanistan was supported across the board. Eventually, the president started making a case for war in Iraq as well. That was much more tenuous, but he did have a bunch of stuff that looked pretty bad (even if we later found out much of it was garbage).

At the time, I was seriously opposed to the war. I was deep into news at the time, and something smelled wrong -- like they were just trying to get a war started but it wasn't really justified. It seemed like they were just trying to hop into this thing they wanted to do and they were using 9/11 as justification.

If anything, I feel like the establishment wanted the war so it was going to happen. One of the big problems John Kerry faced in his presidential run in 2004 was that he voted for the war, just as many Democrats did. Countries opted out of the war, and in the end his "grand coalition of the willing" was made up of like 3 countries so obviously they didn't want to touch that with a 50 foot pole, but America had some legitimacy on the global stage so they somewhat gave America some benefit of the doubt, even if it wasn't clear it was justified.

That being said, with 9/11 right there, and George W. Bush trying to tie the war in Iraq to 9/11, there was a veneer of legitimacy. One the invasion was underway and it became clear how different the reality was from the fiction presented, that's where support fell apart. Keeping in mind that the Democrats did vote for the war, they struggled because they wanted to distance themselves from the war they voted to start, but quickly they pivoted to become the anti-war party until they got elected.

By contrast, Putin is invading Ukraine because "fuck you that's mine". There isn't a 9/11 event he can pivot off of, so while he's making an argument about NATO, it doesn't strike the same. Putin wasn't looking for a "coalition of the willing", and cared even less about international legitimacy than George W. Bush did.

So to summarize, the war in Iraq was something that didn't smell right in the days leading up to it but they kept trying to spray it with deodorant, and afterwards turned out to be a giant sack of crap. The war in Ukraine never really tried to hide the fact that it was a giant sack of crap.