The stakes have never been higher in the Ukraine-Russia war. In the week that saw the conflict pass its 1000th day, Western powers substantially boosted Ukraine's military arsenal - and the Kremlin made its loudest threats yet of a nuclear strike.

He declared that a conventional attack by any nation supported by a nuclear power will be considered a joint attack on Russia.

Russian President Vladimir Putin formally lowered the threshold for his country's use of nuclear weapons Tuesday, after the U.S. allowed Ukraine to strike inside Russia using American missiles.