Caring and Daring,
Why Ukraine, why you cryin'?
Nato so caring, Biden so daring
Putin there, don't you dare.
One foot in, he didn't care
Rush in, he cried, Russians!
It has been a long time since the threat of using nuclear weapons has been brandished so openly by a world leader, but Vladimir Putin has just done it, warning in a speech that he has the weapons available if anyone dares to use military means to try to stop Russia's takeover of Ukraine.