The speedy arrival of CSTO troops in Kazakhstan is unprecedented in the 30-year history of the Russia-backed regional security alliance. Today’s show was produced by Victoria Chamberlin, edited by Matt Collette and Noel King, engineered by Efim Shapiro, fact-checked by Laura Bullard and hosted by Sean Rameswaram. Transcript at vox.com/todayexplained Support Today, Explained by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices