Think about how the Obama administration sees the state of the world. It wants Tehran to come to heel over its nuclear programme. It wants Vladimir Putin to back off in eastern Ukraine. But after recent experiences in Iraq and Afghanistan, the White House has no desire to put American boots on the ground. Instead, with the help of its Saudi ally, Washington is trying to drive down the oil price by flooding an already weak market with crude. As the Russians and the Iranians are heavily dependent on oil exports, the assumption is that they will become easier to deal with.