I don't know why they even bother with these big show events: it's not like they'll listen to the public opinion on the matter anyway, so they should just get on with whatever "freedom" liberation they're planning and save us all the farce that it is somehow justified. They can't even be honest warmongers.
It has worked so well throughout history though. Everything from the Lucitiana to the Gulf of Tonkin to Pearl fucking Harbor. PH was an actual direct attack but we had plenty of advanced notice because their pilots wouldn't stop using their comms. Lucitania was attacked because it was a merchant ship with heavy weapons it should have never ever had installed. Tonkin was "let's pull up to three bad neighborhood and wait to be attacked" sort of situation. People like Bolton have seen this and use it part of their daily job to try and make wars, and it works sometimes.
Of all the things surrounding pearl harbor. I dont recall it being the Japanese comms that gave it away. IIRC they were under strict radio silence for that whole time period.
There was some warning, but it either was misunderstood (such as the early radar warnings) or the messages were delayed.
As far as the lusitania, I dont recall it being armed at all. It was carrying war materials, but I dont think it had any mounted deck guns like you implied.
Iran targeting a Japanese oil tanker during the Japanese PM's visit to Iran makes about as much sense as Assad dropping Sarin on his own civilians while fighting a huge war against US-funded rebel groups.