People are also not supposed to be generally messy, but if Yeerks are only messy and not unclean then they can just wash out their ears in some relatively unintrusive fashion.

Anyway, look, sometimes massacres just happen. They're reds.

He will select his allies from among the countries fortunate enough not to have a massacre just happen to them, then.

Unlucky people need planets too!

He can't win a war with troops so undisciplined that they have massacres by accident. The planets are not a charity service.

...they could not let anyone who did any massacring enlist?

When Andalite soldiers fuck up the people who trained them and the people who commanded them get in trouble because they should have trained them better, noticed that they weren't trained properly, and avoided putting them in a situation where they could accidentally have a massacre. If places have a massacre and then completely reform their training procedures, and discipline everyone involved and everyone who commanded or trained everyone involved then he can revisit the question. 

It'd be more a cop problem than a military problem.

He does not have useful proxies for how they train their troops beyond how they train everyone they issue a weapon in the service of the state.

The military are much more carefully trained! Cops run the gamut from traffic law to homicide detectives.

Then maybe avoiding massacres is as simple as training cops better!

No see soldiers have to work alongside reds, losing a military red because someone got spooked is a big deal, you have to reshuffle a lot of things for that. Cops on the other hand, apart from the handful who have to talk to the autopsy red, do not normally need to deal with reds except to discipline them. Sometimes fatally.

"I'm not clear on why this means that improving police training would not help with massacres."

"It'd involve training huge numbers of personnel for things that are almost never relevant to their jobs, and we don't have a standardized handling the way we do for military training on how to deal with unit reds," says the diplomat from Cene. "We can't even just adapt the process for teaching detectives to talk to autopsy reds; that's a volunteer position and only involves meeting the reds under controlled circumstances."

"Under what circumstances do massacres tend to just uncontrollably happen?"

"When reds step out of line and start polluting things or initiating violence, which is likely to happen in a transition period. Anitam was very lucky, if their reds hadn't believed the thing about decontaminating them they would have had just as much of a catastrophe on their hands as anyone could."

"I wonder if they were more confident in their grey discipline."

"The way I understand it they barely involved greys in the process at all, which means they probably were trying pretty hard to avoid it. And a negligible fraction of their ex-reds decided to be grey - they let them decide, there wasn't even an aptitude test - and those are all dancers and porn stars, no, I don't think their reds liked the police more than anyone else's."

"Have people asked them whether they took measures to prevent riots?"

"Apparently they got rid of social workers, which really seems the opposite of helpful, they dodged a bullet."

"Hmm."

"Obviously no one wants hundreds of red bodies littering the streets, we're communicating a genuine challenge here that won't apply in space combat."

"It's not that I think the specific challenge will apply, it's that it's - highly unusual that it's entirely luck whether you end up killing hundreds or thousands of your people. And there are obvious measures a state highly motivated to avoid that could take, and I do think the attitude of total helplessness about it reflects poor institutional problem-solving skills."

"I mean, we could refrain from having police respond at all to red uprisings but that hardly seems like an improvement. My understanding is that Andalites don't have similar instincts about pollution, but..."

"We have instincts about different things. Do you not have nonlethal means of crowd control?"

"By and large they require those controlling the crowd to touch the people they're controlling at some stage. Police reds beyond the autopsy ones have actually been tried but they're consistently untrustworthy."