©Courtesy of the Sundance Film Festival “Hailed” as one of the most polluted cities in the world, Karabash regularly draws obnoxious YouTubers, who mock its toxic Communist-era legacy. It is exactly the kind of economically-marginalized provincial Russian city that disproportionately supplies recruits and conscripts for Putin’s unprovoked war in Ukraine. Karabash is 1,600 miles from…