You may be right. I don't have anywhere near Sunny's problems but I do have a flagged passport after I fought in the militia YPG in Syria (legal, but I seem to have been put on a list which has caused me endless issues with CBP). Alarm bells ring to the Nth degree when I enter, but as far as I can tell they don't have much mechanism to investigate pedestrians leaving. I'm guessing if they do have something it only focuses on some exceptional cases (like perhaps Sunny).

You are not currently wanted by the government - and only run into trouble after presenting a passport. This is not how a fugitive on the run would exit (or enter) a country.

There is a lot more to the DHS apparatus than simply scanning passports. Most of it is unseen by the public.

I am fascinated to learn more about the apparatus that checks pedestrians leaving the US. I understand there is doubtlessly unseen stuff going on there. Do you have any materials or primary sources I can look at to understand what you're talking about? It has been my experience when crossing after scanning my passport the officer goes from jovial to shocked/unexpected (I don't look like or act someone who would have a flagged passport) which leads me to believe there is at least in many cases no advanced warning to them a flagged individual is approaching.

Now I know the government must surely have these systems but I think it may be doubtful how effective they've set it up to be to stop people leaving the country if by foot. The flow of people leaving the border in general is just way lower scrutiny, in my experience living in a border state. I would be shocked if the average say non-violent felon fugitive has much trouble leaving if they're not on a flight manifest.

How did all that work? How did you hear about it and decide to help? Are you Kurdish? Were you a soldier already? Did you focus on journalism or medicine or sniping or anything?

How does the USA treat that in general? Do the people accept it, or praise it? Do they try to trick you into admitting legal problems with it? You can get back into the USA so I assume you must be a citizen?

What's your opinion on the general legality of fighting in a foreign war by choice?

Did you accomplish enough that you'd do it again?