The Cipher Brief Open Source Report for Tuesday, April 20, 2021

In this episode: U.S. Ambassador to Russia returning to DC; Former VP Walter Mondale dies at 93; Ukraine says Russia will soon have 120,000 forces on border; China moves long range rockets to Himalayan border; China's President Xi calls on regional powers to reject 'hegemonic' global governance style while Human Rights Watch issues new report on abuses in Xinjiang; Chad's President Deby dies in combat one day after winning re-election.