It's a classic trope in epics and in history.

Reason there is always a lot of paranoia from political elites towards military leaders that return home victorious. Generals with a lot of political goodwill from the masses returning home to the imperial metropol with a loyal battle harden army high on a recent victory. Throw into the mix a sense from the military that the political leadership is ungrateful and doesn't value their sacrifices.

It's been around two decades since I read those books but at the end of the formic war wasn't the fk up when the political leadership on earth ordered all the commanders arrested immediately after the final victory over the Formics? Treating them as both a threat and a potential spoil of war to be secured. The preemptive move didn't just fail due to a sizeable percentage of the soliders at the facility turning their weapons on those sent to make the arrests but it had the side effect of radicalizing all the commanders. Even after the situation was deescalated and all of Enders commanders were safely returned home, the damage was done and they had been set on a course that would only end with the eventual military coup d'etat of earths political leadership.