AI's will tend to give you almost anything for a few ships when there in the middle of a catastrophic war - and while that makes sense they'll also trade you ALL of there planets and technology if you give them enough ships. I honestly think there needs to be a cap on the number of planets that they'll trade (say roughly 10% of there empire for perhaps a 300% increase in there current military strength)... Anyway just a thought - this just needs some rebalancing