Final answer:
Britain and France went to war with Egypt over the nationalization of the Suez Canal in 1956.
Step-by-step explanation:
Britain and France went to war with Egypt in 1956 over the nationalization of the Suez Canal. Egypt's President Gamal Abdel Nasser decided to nationalize the canal, which was previously under British and French control. This move threatened their interests and led to a joint military intervention by Britain, France, and Israel. However, international pressure and the threat of Soviet intervention forced them to withdraw, marking a significant moment in decolonization.