Early 1939 did not offer Britain a single obvious naval war to prepare for. A German war placed U-boats close to the home islands and created an immediate requirement for large numbers of Atlantic convoy escorts, although Germany's submarine program was only gradually expanding. A Japanese war instead centered British planning on sending a major fleet to Singapore to block access to the Indian Ocean, with additional forces guarding routes around southern Africa and Canada. Uncertainty over the first enemy affected fleet deployment and the number and type of escorts that appeared most urgent.
Notable Point · 4:01-5:41
Germany, Japan, and two different escort problems
British planners still faced uncertainty over Germany or Japan as the first enemy, and each scenario demanded a different distribution of escorts and fleet forces.