Oil prices jumped about 4% on Thursday, and the reason is geopolitics.

The United States imposed fresh sanctions on companies and individuals trading Iranian petroleum products, part of its Operation Economic Outcast campaign against Tehran. Markets fear any disruption to supplies from the Middle East, which produces a large share of the world’s oil.

The Strait of Hormuz, a narrow waterway carrying a fifth of global oil flows, is the market’s biggest worry. When tensions rise, traders add a risk premium to prices.

The spike matters for India, the world’s third-largest oil importer, because costlier crude widens the import bill and can push up fuel prices.

Prices eased later after President Trump said the US would not strike Iran before the November midterms. For now, analysts expect volatility to stay high.

For Indian consumers, the immediate question is whether pump prices will change. The government and oil companies have kept retail fuel prices steady through recent swings, absorbing the volatility for now.