First read this Clickhole article about Bernie Sanders. Yeah, it’s gonna get political, because that’s what my problem is with GATE. It might also get spoilery so consider yourself warned on both counts.
It would not be fair to boil down GATE as a simple power fantasy about Japan and its SDF arm doing what it’s good at doing. But unfortunately there’s not a whole lot to go on in GATE in the theme department. It is a very pure kind of wishful hypothetical.
Unfortunately that sort of thinking also is sort of what Japan’s Asian neighbors find abhorrent about Japan’s behavior during WWII. You can ask the people of Taiwan, for an example, on how they felt about being Japan’s model colony for roughly 40 years. Yeah, model colony. I believe the Japanese can do a way better job as a colonial power than many European countries of the day, too, so this I share with GATE’s SDF author. It might not even be too different than from what you’d get if you asked the hapless farmers and tribals the SDF rescued in the show. Of course, that’s missing the point.
What’s missing from GATE are all the important stuff that sort of spoils the fantasy, basically, just like how a statement is missing in that Clickhole article about propping up puppet dictators. Or colonialism is problematic and inhumane. Or you shouldn’t really write a story where the SDF basically installs a puppet government. FWIW there are some recent movies where the bad guy’s end game is to do this! I don’t think Japan’s public has gotten that memo on colonialism yet. To be fair back then they didn’t have the internet! We’ve long since moved on from it! Maybe Japan’s post-war generation failed to take note on international politics and explained how things work to the Lost Generation because they were too busy building their economy? “Yo guys, but we’ve gone from colonies to just plain dictators that we prop up that serve our international interests, and proxy wars like Syria.”