The Golden Age of Piracy lasted between 1650s and the 1730s, and it involved most of the oceans and most ocean trading nations.

Board or sink anyone who don't surrender to the extortion. Flags only work if nations respect them, and nations that are willing to pirate ships is very unlikely to respect flags.

The Hormuz strait is now basically the same as coast of Somalia, except that now the pirates has missiles, rockets and torpedoes.