The Russians reported a year ago that the CIA was recruiting from ISIS for terrorist attacks.
And the CIA recruiting ISIS to fight in Ukraine goes back to 2015, and is from the NYTimes.
https://www.europarl.europa.eu/doceo/document/E-8-2015-011933_EN.html
Keep repeating your nonsense.
Show us evidence right here and now that the United States was involved in the recent terror attack on a Moscow concert.
Evidence or go to hell.
Not what Russia said in 2015.
Evidence regarding this terror attack.