Russia and Saudi Arabia, two of the world’s three largest oil producers, formed an unprecedented alliance (the Vienna Alliance) in 2016 that allowed them to lead OPEC and non-OPEC producers to jointly agree to coordinated supply. The cooperation has continued, with the Alliance agreeing in December to cut supply again. What brought these two oil superpowers together after decades of failed attempts at joint supply management? What might sustain this alliance, and what could eventually pull it apart?