Putin sent a nuclear armed frigate into the Atlantic to threaten a nuclear attack on the US, WWIII, because he understands that he has no hope of prevailing in Ukraine as long as the US and other Ukraine allies continue to supply Ukraine with weapons, and, ridiculous little man that he is, he hopes to frighten the US into ending its support for Ukraine, so it is not a show of force but a sign of desperation about the war in Ukraine. Putin has only two choices, admit defeat in Ukraine and withdraw, or start WWIII and see Russia destroyed.