What really counts is what President Putin does next, writes the BBC's Steve Rosenberg.

Summary

The U.S. has approved Ukraine’s use of long-range ATACMS missiles to strike inside Russia, drawing sharp criticism from Russian officials, who warn of serious escalation and even invoke fears of World War III.

Kremlin spokesperson Dmitry Peskov condemned the move as a “new spiral of tension,” while Vladimir Putin has yet to comment.

Putin previously warned such actions could be seen as NATO’s direct involvement in the war.

As Biden’s term ends, speculation rises about how Trump’s more cautious stance on Ukraine aid might influence Moscow’s next steps.