The IMF is relaxed on the economic outlook for the two largest GCC economies, Saudi and the UAE. But rising global protectionism presents a left-field risk.

The latest IMF forecasts downgrade Saudi growth for 2017 to just 0.1% (from 0.4% three months earlier) and to 1.1% (from 1.3%) for 2018.

The IMF’s 24 July update to its April World Economic Outlook, blames “Saudi Arabia’s commitments under the Opec+ agreement” for the underperforming GDP, though this is based on...