You have to be kidding me, right? Just by joining the military of your nation, you are joining a group of individuals that have decided to protect the laws of that nation. It's one of the few things that I agree that the US Constitution says the Federal government can do.
And that "pos document" is the greatest work ever written by man. Turns out, its man that has abused that document and have somehow turned it around. It was specifically written to limit the powers of the government and the modern politician has somehow flipped it to limit the rights of the people. The modern-day politician is so afraid of living as the Constitution is written, so they belittle the Libertarians & Constitutionalists as 'fringe' or, 'homegrown terrorists' when all we want is to continue to have the document limit the power of the government.
Again, you, just like absent, are looking at the way the modern-day politician is abusing the US military and are blaming the military for what the politicians are doing.
The bases in Japan were written in the treaty Japan signed when we fuck smashed them in WWII. They were not allowed to have any sort of standing army and just in case you were not aware, Japan went full retard on all its neighbors prior to signing the treaty so, the US told them that we would be its military because the second we left their shores, Japan would have been invaded and its people slaughtered. Hell, Korea and China are still itching for blood against the Japs. Yes, they did have a small military but they would have been overrun by the smallest of militaries were it not for the US stationed there.
For all the other foreign military bases - you are asking the wrong person as i have been extremely vocal on this board about shutting them all down, except for Japan.