If Japan had attacked Britain but not the United States—Churchill’s nightmare scenario and one that Hitler had promoted in 1940 and early 1941—it would have been an even greater disaster than British planners had expected. Roosevelt would have struggled to persuade the US public to join the war. India might have fallen. A linkup of the Axis partners in the Indian Ocean and Persian Gulf would have been quite feasible. British resources would have been stretched to the breaking point, damaging Britain’s capacity to fight Hitler.
