Since over 2 years, we again live now under the constant real threat of a nuclear war. Or this is at least what Russia is regularly claiming. This is very current as long as Putin doesn't get his s** together.

Of course there are other current candidates who would also deserve it, but I think it might be also a matter of how hot and current the problem is, and how much political impact this message would have. Russia and their threats are cooling down for the moment, so it's "safer" to send this message, instead of anything related to the Middle East, for example.