A new week of the coronavirus crisis began with another unexpected consequence — an oil price crash driven by the outbreak of relatively unrestricted economic warfare between Saudi Arabia, Russia and the West.

Oil futures saw their largest fall in a single day on Monday after Saudi Arabia announced it would begin unrestricted oil production, an apparent strike at Russia. That followed a spat between Moscow and Riyadh at an OPEC meeting on Friday.

Then, paradoxically, Russia was refusing a Saudi suggestion to cut production to keep prices higher, arguing that recent falls were pressuring the United States and other shale gas producers that Moscow would like to see go out of business. The Saudi retaliation — playing Russia at its own game — takes advantage of its own greater production capability and lower margins to launch its own attack on the Russian energy sector.