Ah yes, "defensive action".
Only problem is that the countries in the Gulf are already
passive participants by hosting the US military carrying out the war of aggression against Iran.
Which is a very strong casus belli for Iran, giving them the right to attack these countries, including establishing a naval blockade.
But let's not pretend about that.
At the end of the day non of that matters though, the populations of these countries are far too chauvinist to care for such things, not supporting a war of aggression is simply incomprehensible to the average European.