Remove, nice euphemism. In the actual movie no genocide occured, violence ended and reconciliation began whereas you seem to be eager to eradicate the hippies because, well, because you don't like them.
Trading with a recent winner of a civil war is not somebody the Feds do, let alone indirectly encourage side A to eradicate side B via the promise of commerce ... and thus take sides once again. And this is the crux of the issue, the total neglect of rules, ethics and consistency of the anti-Picard faction.
Anyway, I hope you understand at least now why the Sona lied to the UFP. They knew very well that telling them the truth would have stopped the Feds from cooperating with them.