Opec has no good market management options ahead of its get-together in Algiers later this month. Record output from Opec itself has pushed any hope of a market rebalance out to late-2017 at best and Brent prices down to $46/B. Even a notionally successful attempt to support prices will only push rebalance back further, cannibalizing the organization’s future revenue for short-term gains.

The IEA’s latest oil market report projects for the first time that global oil supply will...