She couldn't grant sanctuary until he proved that being forced to live was an intolerable cruelty, and they wouldn't let him die until he was granted sanctuary.
Tom fired heavy yield weapons at a power station. That's just a stupid idea, and it didn't matter how safe he played it, there was always a chance he could have destroyed the ecosystem slightly faster than it was already being destroyed by the power station.
Imagine if Iran got on it's high horse and decided that irresponsible America was no longer allowed to use Nuclear Power because, even when it's used correctly it's grossly irresponsibly damaging to the planet?
How exactly do you think Iran would be thanked for systematically removing all the American Nuclear Power stations for the national grid by force?
No, I'm serious, if Iran can't suggest that other countries also be denied Nuclear Power, then the world is just picking on Iran.
No one likes a bully.
This is so the non interference policy which might be the Prime Directive.
Paris turns his agitation to the captain. "We can't just let this go!"
"What do you want me to do?" Janeway asks, softly-that "someone's about to die" softness, like when a rattlesnake stops rattling just before it strikes.
Paris snorts with disgust. "Of course. The almighty Prime Directive," he scoffs.
"Would you please excuse us, Lieutenant?" Janeway says. It's not a request. Torres leaves, with a farewell to Tom. "I'll see you later." The door closes.
Janeway rises from her seat, and stands nose-to-chin with her conn officer. Her voice is dangerously even, excruciatingly soft. "I know you're upset, Lieutenant, but when you're in a room with me you check that attitude at the door. Understood?" Tom tries to interrupt, but he's no match for her. "We can't expect an entire society to change because we think they should."
But this episode did seem to be about the Prime Directive and it did apply to a post warp culture which happens all the time in Voyager.