You know, the irony is that as long as the US and the West in general had an interest in keeping an even bigger enemy (Iran) in check, they had no moral objection to providing Iraq with all kinds of assistance, financing, equipment, materials, and training on developing the very same WMDs they later invaded Iraq for having, even if it was known they were destroyed.
But you'll always get exactly the story you need to hear to support the conclusion you should support. And you will support it because people care less and less about critical thinking, collecting available info from both sides. It's so much easier to just get the conclusion in predigested bytes, ideally just a punchline. If this kind of "thinking" is enough to make people storm the Capitol of the US, it's enough to get the to support the invasion of a dusty corner of the world most of them couldn't even point at on the map.
Having a justification doesn't mean it must be a good justification. The WMD that didn't exist? Being the close ally of the country that actually supported 9/11?
Let's not keep going on the same beaten path which will not suddenly give us a different answer. For more than a century the US has been involved in affairs everywhere else in the world long before everyone else in the world was involved in any US affairs. Both 9/11 and the subsequent invasions (or the acts that came before) were just as much terrorist actions but if you creatively draw the line you can arbitrarily erase any inconvenient action that came before. If you draw the line at 2002 the invasions look unprovoked. And if you draw it in the early 1980s then 9/11 looks like soldiers defending their country against further attack. Who would you say first meddled with whom to trigger the chain of escalations that came after? But no need to dig, ask yourself as a decent human being: should you bomb a wedding and call it defense?
If you had heard as often as I have people justifying the unjustifiable (then and now) you'd understand what's the problem with arbitrary lines and pro forma justifications. I apologize if a comment box cannot support any better explanation despite the unshakeable foundation for what I said.