Are you sure about that? When Russia annexed Crimea firing a couple of shots in 2014, we couldn't see all that horror you talk about, so I don't think it would be what would happen. In fact, there's a lot of people in Eastern Ukraine that has been hoping for Russia to start this military operation.
OTOH, we have records of killings and rapes by American military personnel in Iraq when the US invaded the country back in 2003. And they did that unimpeded. Maybe you supported that invasion.
It's time to double down and hope Russia gives up Crimea like they just abandoned Syria. Even Donald Trump is not stupid enough to miss an opportunity to play his enemies against one another.