US (and other NATO countries) didn't just "help". They hit the ship themselves. Russian intelligece indicates (and the Russian media reports) that there are 40 countries sending weapons to Ukraine. I can't say that I understand why the Russians aren't constantly flying over the border and targetting anything that comes across that isn't obviously civilian. Of course, they could be smuggling weapons in via vehicles designed as peaceful civilian vehicles (18-wheelers and the like purporting to be delivering food or other goods).
Lots of right-wingers in Russia are insisting on flattening Ukraine and even nuking NATO military bases.
Putin is showing a lot of restraint in that he's being attacked from the right for being too soft on Ukraine and NATO ... as he continues to try sparing civilians. Russia has enough weaponry to turn Ukraine into a sheet of glass within 15 minutes, but Putin has a conscience.