Gowron become high chancellor by following klingon law aka he was the legal government.
The federation - Picard - was heavily involved in electing Gowron to the high council, treated with his as the legitimate government, etc - meaning it recognized him as the legitimate government.
Both Gowron and Worf
mention the treaty
, as the basis of their request.
mentions the prime directive
when he refuses Gowron. NOT the treaty.
All implicitly confirmed the treaty allowed for federation intervention in internal klingon matters, when its help was asked by the klingon government.
Of course, the distinction makes little difference to my point:
"About the prime directive (or the treaty, if you prefere) - you can't involve youself in internal matters of a culture, but you can interfere in this culture's relations to political actor X (despite the fact that you're not a paricipant in these relations)?
A harebraind distiction
In both cases, Gowron asked for federation intervention and the Duras house opposed it - no distinction here.
T'Girl, you still have not adressed:
"Picard saved the day only because the romulans acted equally opaque:
One wonders why, after Picard&co found the romulans, Sela didn't say:
"You found me. Big deal. I just returned from your ship, Picard. You know nothing you didn't already know.
This changes nothing - this is not hide and seek; I have no reason to return just becase you see me.
If you have the balls, open fire.
If not, get out of my way. I have a war to win. And, when I'm done, I'll come with my new klingon pals and start taking federation worlds apart.""