If the Cardassians get greedy, remind them that:
- We're stronger than you.
- We have Klingons as allies.
- We have superior technology.
- We're more numerous than you.
So on and so forth.
This is the mistake I think a lot of Trek fans make. The Cardassian are not, repeat are not, weaker than the Federation, they can't be. These two interstellar power fought for decades, the Federation didn't in that time roll over the Cardassians. If the Federation were superior in technology and numbers at the very least Starfleet would have destroyed the bulk of Cardassian military starships. Obviously they did not.
The Federation eventually signed a treaty that all agree was a compromise, the Federation didn't dictate terms to the Cardassians, which they had not choice but to accept.