So I wake up to this: Detained Iranians Had Iraq Approval , US forces carry out provocative raid on Iran’s consulate in northern Iraq (and yes, I realize it happened before today, apparently I forgot to get my Google News quota yesterday).
Now, to be fair, the precise status of the personnel and office is unclear. The Guardian UK reports it was: "a liaison office that had government approval and was in the process of being approved as a consulate." As a basic rule, once the host government has granted immunity to persons or premises, they become sacrosanct. As the UNITED STATES DIPLOMATIC AND CONSULAR STAFF IN TEHRAN (UNITED STATES OF AMERICA v. IRAN) case shows, the US is very particular when it comes to their own diplomats (as well they should be). Of course, the US is also infamous for not respecting diplomatic/consular protection* but I can't remember them ever breaching immunity before.
* E.g. in the LaGrand case and the Avena case. And for a hilariously meglomaniacal twist, see the American Servicemembers' Protection Act.