Fertilisers are not just an agricultural input: they are a strategic resource hidden at the centre of geopolitical conflict. The US and Israel’s war on Iran and the related disruption of shipping through the Strait of Hormuz are sending shockwaves through the global farming system. A large share of the world’s traded chemical fertilisers normally passed through this strategic chokepoint, alongside key feedstocks needed to produce fertilisers elsewhere, such as gas, ammonia and sulphur. The rise