The Organian Peace Treaty

[NAHTMMM]

1. That's a good question. I suspect that Kirk & the Federation would have wanted to invade the planet / drive off the Klingons, but was there enough Starfleet in the area to mount such an attack any time soon?

2. The Federation/Klingon fighting was near enough by to cause the Organians pain. That's why they got involved. Presumably the Romulans and others aren't so near to what the Organians consider their territory.

3. Presumably they didn't want to attract attention or curiosity. Possibly because they wished to be left alone, possibly because they wished to leave the 'lesser-evolved' races alone (sort of a Prime Directive thing), possibly for some other reason.

4. We really don't see canonical evidence of how heavy-handed the Organians were in enforcing the treaty. They may have been only intervening when necessary, to prevent full conflict, and once they liked where things were going (towards that future friendship) they quietly removed themselves from the situation. That's how I assume it was, anyway.