There are no "warriors" compatible with the UFP. They don't even make decent soldiers. They're pretty much inept...
...You're right. The Prime Directive doesn't apply. They don't even hold themselves to it, when it becomes inconvenient...
...so arrogant (because, no matter what they say, the Federation is basically run by one species--Homo sapiens)
Wow, you really don't have a very high opinion of the UFP. Seems like in your book it's inept at defending itself, hypocritical about its core principles, and arrogantly elitist about species diversity. Why would anyone want to live there?
For my money, I prefer to continue to think of the UFP in the more traditional "utopian idealism" mold that's been part of Trek from the beginning. It may not be perfect, but it's still the best government we've ever seen — post-scarcity, post-capitalist, post-imperialist, post-racist, and generally doing the most good it can for everyone involved. It's that optimistic vision of our capacity to improve ourselves and our society over time that makes the whole thing interesting. Without that we might as well be watching nuBSG, telling us that we can't avoid making the same stupid mistakes over and over again.
I'm aware of [universal jurisdiction], and it DOES NOT APPLY. Our real-world international politics, and even their interstellar politics, cannot encompass what we're talking about here. We're not talking about prosecuting someone from a different location. We're talking about prosecuting someone from a different universe. I get that this is science fiction and all and is supposed to be allegory for human institutions, but come on. That's still not a light distinction.
How so? That's not a facetious question: I'm completely serious. What actual difference does it make that it's a "different universe"? You can get there (and back again) by starship and by transporter, as we've seen more than once. As such, it's
just another place. Heck, it's a more accessible place than (say) the other side of the Milky Way, despite that being (relatively) close in terms of our own universe. So if there are certain principles of law and justice that are so important that they transcend the dividing lines between one place and the next... town, or state, or country, or planet, or star system... why should "universe" be any different?
(And whether the system imposing justice is "threatened in any way" has nothing to do with it. It's not about self-defense, it's about upholding principles of civilization.)
EDIT: Something just occurred to me. Burnham is guilty of kidnapping. Not only kidnapping, but kidnapping a head of state.
Yeah, on this I'm inclined to agree with you. Technically I think it's arguable that Georgiou wasn't a head of state any more, as she'd been deposed and was not in a position to take the throne back... but it was still kidnapping, against Georgiou's will, as expressed only a few seconds earlier, that she wanted to stay and fight. However, as the Terran Empire is now presumably engulfed in civil war and has no functional government, jurisdiction over Burnham's actions would fall to the UFP... and I think it would be likely to hold that Burnham's offense was mitigated by the stakes involved — i.e., saving the life of a sapient being through the only means available — and by the fact that she released the abductee to proper legal authorities at the first opportunity.