Errm, the lopsidedness is in the Klaestrons' favor -- they can extradite whomever they want (in this case, Dax) from Federation territory without needing UFP permission. Why would the UFP have forced such a treaty on them? If anything, it suggests the UFP was bending over backward to accommodate the Klaestrons. Which raises the question of why they'd do that.
Hmm, that's a good point.
It jsut seems striking to me that the Federation would have signed a treaty that allows significantly less powerful parties with close links to Federation opponents the right to enact extraordinary renditions of Federation citizens on Federation territory. I can't think of any Earthly parallels--Cold War-era Yugoslavia wasn't given the right to do that in any Western bloc country that I know of, say.