Grabbing someone's phones and hurling it aside is assault for mere mortals, but since it's Donald, he's special, I guess. People have been discussing revenge and retribution, because there has been no justice, so far. This is an example of Trump being above the, law he should have been arrested for criminal assault.
In Ukraine there will be no justice for the war criminals either, so it is perfectly acceptable to hunt them down and inflict retribution upon them. In war retribution is the only justice and deterrent. It's why Hitler didn't use chemical weapons in WW2, the brits made it very clear what would be falling on German cities if they did. Likewise, Vlad is reluctant to use nukes or chemicals because of retribution, not because he has a conscience.