The red text is what it comes down to. After 9/11 the initial outrage made it pretty easy to justify almost anything, including our "Patriot Act". Over time an intelligent person, hopefully, thinks about things and reviews facts, data, legal developments in different areas, developing markets, corporate strategies, and a few other things that cause a picture to lose its clarity. When you are part of the kill chain that takes lives of people you know are innocent it gets a lot harder to stomach. It's easy to talk glibly about "collateral damage" but when you take the lives of children and blame their deaths on being associated with a "bad guy" it gets hard to sleep at night. What you have seen and done never, ever goes away. That part of what PTSD is made of.
If we take a step back and look at what has been taking place for the past decade we might come to the conclusion that thousands of people have been killed that have never set foot in our country or had any involvement with "terrorism" in our country. Their primary "guilt" has been in disobeying rules and resisting controls placed upon them by an occupying power. Afghanistan is very much an example of a conquering power imposing it's will on a perceived "weaker" country. After bin Laden was killed we had no further reason to maintain a presence in Afghanistan. Our only purpose from that point on was to force them to shape their government to one more in alignment with ours and to obtain something we want or need. Comply or die. Afghani’s don’t have much need for a government as their religion is the foundation of their lives, not government, and the people are largely self sufficient. The fact that we, like so many "conquerors" before us, has failed suggests what we are doing is not what their population wants, or will tolerate. Yes, we have most definitely failed, with the only reason for our continued presence being to keep the flow of money moving between defense related businesses and various nationality government related personnel.
Why try to force populations of other countries to our will? In my mind it comes down to power and control over a people in order to take something from them. The very few people that have made the decisions that placed and keep us in these countries, along with the decisions to kill everyone that defies them, are very, very accustomed to an extremely high standard of living that is financed by the people over which they rule. Governments can't function without money and governments obtain their money from the people they "govern", or from people that leverage a government to give, award,guaraantee them something they want. Iraq is another that was of little threat to the U.S. Very much defiant but not a threat considering that most of their military might was decimated during the Kuwaiti conflict. Unfortunately ISIS was created by a failure to "follow through" in Iraq. The decapitation of the government and quick departure created a power vacuum, much like the one that was created in Libya. We should not forget how Libya was handled. Nature abhors a vacuum.
So having spent plenty of time in both Iraq and Afghanistan, along with some other unpleasant locations, so I'm afraid my perception of what we have been doing has become more than a little jaded. I've seen and done too much to think for one hot second that what we are doing is for the benefit of the people that live in the countries we have tried to decimate. Shoot, people don't have any understanding of their cultures. If we did we would not have gone about things the way we have as in so doing we have created multiple generations of people that will never forget or forgive, seeking vengeance until it is satisfied. Their culture does not allow forgiveness.