Opec output fell 180,000 b/d in February, with Saudi Arabia again the driving force. But the group remains more than 300,000 b/d above its target level, and limited compliance may threaten the prospects of the output target being renewed in May. Saudi Arabia has been burned before by bearing the brunt of output curbs while fellow members maintain production; it does not want a repeat.

Arguably the latest production figures from non-Opec Russia are the most concerning for Saudi Arabia....