Everything becomes behind-the-scenes with social manipulation and gradual political takeover and the like.
This allows the obvious and readily evident approaches of "sudden" invasion to be deemed unacceptably "barbaric" despite other forces having the same objectives with no less diabolical, yet far more obscure means of achieving them.
This was the sentiment behind a snarky post I made not so long ago, admiring an obvious "old-fashioned" invasion. It is of a type where it must be owned with no hiding or denial. The world sees it readily. Everyone knows the intent. There is no confusion about it, no deciphering of its intent required.
All war sucks, but it's that other kind, contrived behind the scenes, often in mountainous regions of special political status, with various asymmetrical expertise and mass-manipulative psychological understandings gained through not so legal means, which, in the long run, becomes the most poisonous kind of warfare, and the most detrimental kind to the entire planet.
Kirk using my 2001-era flip phone is still a trip. Dream it, and a bunch of science-oriented autists will eventually make it a reality. For better or for worse. (They usually don't really care about that whole Gattaca complication-to-humanity's-future part of the equation. That's why corporations value their brains and loyalty.)