Russia and Ukraine

[Leonardo17]

And it's America's fault that the Taliban are now in control of Afghanistan, too, right?

Well, America invaded the country, spend a trillion dollars and ruined millions of lives in order to defeat the Taliban. 

And as soon as America left the country the Taliban took over. 

So how do you describe this, if not as a gigantic failure?

I think you are right on this. And you are right on Iraq too. I mean in terms of international Law at least. The only difference is that Saddam or the Taliban had nothing that is defendable. So the invader could have been China or Russia I wouldn’t really care.
 
But the Ukrainians are a modern nation with a rule of law and a democratically elected government (Since the Maidan revolution). They are like the pro-democracy forces in Syria. So for the general public it matters who is fighting and for what.
 
Another example is the Vietnam War. At that time, it was basically the Vietnamese who were fighting for their homes so at that time, (for many people) the US was the villain.
 
But I agree on this: Bush created a precedent that was cleverly misused by a person with bad intention like Vlad Putin. In terms of international law, it is true that the US did not have the right to invade Iraq. But I’m not a politician. I can’t really discuss the details.