The base chain behind Britain's planned war with Japan

Britain could support carriers from dense infrastructure in the United Kingdom, Gibraltar, Malta, Alexandria, and the Suez region. The chain became thinner at Bombay, Ceylon, and Singapore, where funding and colonial investment constrained capacity. Planners expected Hong Kong to be besieged or lost in a Japanese war, and they could not rely on Weihaiwei as a secure advanced base. Their notional system used Singapore as the regional entry point, Hong Kong as a convoy-routing or recovered base, Weihaiwei as a theater base, and an additional forward base in Korea to help impose a blockade. Unicorn made sense because multi-carrier groups would otherwise have to operate thousands of miles from Britain's industrial base with little heavy aviation support.