When fertilizer flows are disrupted, the effects move through global supply chains in ways that are difficult to contain. Reduced fertilizer use is likely to result in lower yields and translate into higher prices. It is a pattern we have seen before, and geopolitical pressures are once again creating the conditions for a food security crisis. Conflict in the Middle East has disrupted global fertilizer trade, with up to 30 per cent now unable to pass through the Strait of Hormuz.