US ambassador in Moscow tells US citizens to "leave Russia now" or "think of a plan for how to do so without the help of the embassy."
UPDATE 1:36 PM EST --
RUSSIAN DEFENSE MINISTRY: NATO PLANES ARE CONDUCTING RECONNAISSANCE OPERATIONS FROM POLAND FOR THE BENEFIT OF THE UKRAINIAN ARMY
(HT REMARK: See where this can go? If Russia decides that the U.S. is actively helping Ukraine wage war against Russian troops, then the US is a "participant in hostilities.")