From what I've gathered this woman objected to a small protest on the sidewalk outside the Russian embassy in Washington, D.C. yesterday. She argued with the Secret Service that the pro-Ukrainian protesters had no right to be there as it was sovereign Russian land. (The spontaneous protest came after Russia launched a huge missile attack against Kyiv and other Ukrainian cities, killing 14 civilians and injuring 97.) Not happy that the protest wouldn't be stopped, the woman spat in the face of one of the Secret Service, earning her a well-deserved arrest no doubt.
Viktoriia Savchuk, a PhD student at the University of Maryland captured the video.