Seldom has the fog of war lain so thick.

The week began with Joe Biden authorising the use of American ATACMS missiles inside Russia. Or at least that was what the American papers reported, the White House neither confirmed nor denied the claim.

Initial reports said the permission was restricted to strikes in the Kursk region. But overnight on Tuesday Ukraine hit a Russian ammunition dump further north in Bryansk.

Then, Vladimir Putin signed into law a revised nuclear doctrine that said America would be considered to have attacked Russia if it assisted Kyiv. But retained exceptionally high thresholds for nuclear use.

So, who is threatening to do what? Should we be frightened or reassured? And should we be ready for a nuclear war?