While extracting Ethan Hunt, unidentified assailants rain bullets on the car in which Ethan, William Brandt (Jeremy Renner) and the Secretary (IMF) are traveling. One of the bullets hits the Secretary in the head, killing him instantly.
I am puzzled, because killing a diplomat from another country would be usually considered an Act of Aggression or even worse, an Act of War against the diplomat's country. But in the movie there were no repercussions mentioned from the USA. Even though tensions were running high between the two nations due to the Kremlin bombing, it couldn't have been reason enough to massacre a diplomatic convoy.
Is this a simple plot hole which I'm reading too much into or is there some International Law in play that I am unaware of?
NOTE:
I am considering the Secretary as a diplomat as he mentions in the car that "yesterday I came to Moscow to accept the Order of Peace...". This indicates that he was on an official diplomatic mission.
The assailants though unidentified can be easily linked to the Russian police/military/special forces as the person who had detained Ethan in the hospital was later seen issuing orders to them.