Pompeo means the Royal Marines will enforce sanctions

JEDDAH: US Secretary of State Mike Pompeo on Friday said that sanctions on Iran have been effective and “we will enforce them” everywhere.
Pompeo spoke at a regional youth leadership program in the Thai capital of Bangkok during a wider meeting of Southeast Asian nations with world powers.

Somehow the UK started the war with Iran, and the UK is sending ships to the straits.  It is Iran that enforced retaliation.  If Boris Johnson is too stupid to figure this out, then the UK is in real trouble.  Step one in being prime minister is to understand what an act of war means.