What do these people think is going to happen to Ukraine’s ethnic Russians if they’re forced back into Ukraine?

They will not think anymore. The ideology will be changed and Ukraine will become a distant, hard to remember memory just like Libya, Iraq, Syria, Afghanistan, Yugoslavia…

Do not underestimate the ability of settlers to be able to compartmentalize the world so effectively that all violence becomes buzzing static.

which happened within the lifetimes of most of the political class.

Don’t also underestimate the ability of settlers to hold a grudge and be paranoid.