Treaty question

[LeTharg]

I'm considering proposing a treaty of subjugation or protectorate as an alternative to destroying a weaker opponent. These treaties treat the sides differently but I can't tell from the screen whether I'm the one doing the subjugation or being subjugated.

Is it always the stronger empire (in terms of score?) that does the subjugating or protecting regardless of who initiates the treaty? Or do I have to get the other side to initiate the process?