When George W. Bush did his infamous "Mission Accomplished" stunt,[1] he was sort of right. The "war" had been won. The trouble was that there was no plan for what to do next. The occupation was managed poorly and the insurgency had a chance to grow turning what really was a quick victory into a protracted "war."

[1] https://en.wikipedia.org/wiki/Mission_Accomplished_speech

Of course, the real root cause of many subsequent troubles and years of war is that there was no reason to attack, even less invade, either Iraq or Afghanistan after 9/11. GWB just had to do something to show that he protects Americans and retaliates against enemies. So, he did that. And it was a big mistake on many levels.

Iraq? Perhaps not. But Afghanistan was sheltering Osama Bin Laden, and would not hand him over (or even expel him). Leaving him free to operate after 9/11 did not look like a good option.

You can argue the supposed need of invasion either way. That had no bearing on why it took long though.

America won the war, but lost the peace

They were telling people that at the beginning of the civil war. Houston and Sherman were laughed at for thinking otherwise. This was also the thinking before each of the world wars and Vietnam.

You would think people would be educated enough to see through that bullshit on its face regardless of what politicians say. I don’t have any sympathy for people lacking this ultra basic level of education.

To be fair, the people lying about how long war takes are the same people in control of the education.