The Japanese knew, much like the kilrathi, that the US (confed) could muster an incredible amount of raw material, resources and manpower once the sleeping giant had been awakened and the industrial machine picked up speed. THey knew that if the war was not over by the end of 1942, they had lost. Yamamoto expressed this explicitly in a letter to the Emperor written before Midway...
The ultimate plan of the Japanese was to strike at Alaska and the west coast, while the Germans would land in eastern Canada and join them. Together they would push south and east to as they said, "Dictate peace terms in Washington"...
All in all, the Kilrathi are so similar to the Japs that at times it is sickeningly unbelievable and in my opinion does not add to the originality of the race. Everything from ritual suicide to honor to the surprise attack at McAuliffe... But WC was always intended to be a World War 2 simulator in space, CR said that even back in '91...