Japan expected Britain to be distracted

What was Japan’s plan for dealing with Britain while pursuing Southeast Asian resources?

Japan expected European war to distract Britain; British strategy could instead favor a slow advance that strained Japanese supply lines.

Japan's prewar expectations of fighting Britain and the United States differed from its wartime assumption that European commitments would constrain Britain. Pearl Harbor was meant to buy time against the Americans while Germany and Italy kept British ships and resources occupied elsewhere. Before the European war created that opportunity, Japanese planning expected Britain and America to approach through the same broad attritional problem. British planners responded with a measured advance that would force Japan to burn supplies while British logistics remained closer and more reliable. American War Plan Orange also evolved away from an automatic rush, showing how both opponents could adapt once they recognized the trap in the original Japanese expectation.