A large percentage of the world’s food supply is traded through 14 international trade “choke-points,” and are increasingly vulnerable to a variety of threats, a U.K.-based think-tank says in a report released today.

According to the report issued by Chatham House, 25% of the world’s food is traded internationally, with some countries so reliant on this system that any sort of prolonged disruption could have catastrophic consequences.

Climate change, terrorism or other security concerns, and local and regional politics are the three biggest threats cited in the report.

Critical chokepoints are places like the Panama Canal, the Straits of Malacca, and the Turkish Straits, where massive amounts of wheat, maize, rice, and soybeans pass through on a daily basis. As an example, around three-quarters of Japan’s maize and wheat transit through the Panama Canal and one-third of South Korea’s wheat and maize pass through the Suez Canal, Strait of Bab al-Mandab, and Strait of Malacca.