From our friends at Threats Watch - Qods Force, Karbala and the Language of War.

There are strong indications and surrounding circumstances that point to the January 20 attack on soldiers from an American Civil Affairs Unit in Karbala, Iraq, was an operation planned and carried out by members of the Iranian Qods Force extraterritorial unit of the Islamic Revolutionary Guard Corps (IRGC). Four captured US soldiers were later executed by the attackers. If Iranian Qods Force operators carried out the attack and executions, the US response can be seen as a barometer indicating how the US will deal with the state sponsor of terrorism on the Iraqi battlefields and elsewhere in the world...