This. Russia doesn't just shrug off murdered ambassadors like we do.
Yup. The standard caveat about Putin's history, but notice he isn't talking about going to the UN, calling meetings, looking to see what video set this off, or sending out hashtags. His statement today said that they are "taking revenge".
It's the kind of thing that keeps to a minimum people from F'ing with you. It's actually what I'd like to see come from our leaders, Mattis style vs Putin style, in similar circumstances.