Both japan and germany were hoping for some sort of last ditch punch in the nose that would wake the allies up to the fact that this war could continue for years if you didn't come up with a better peace deal. Franklin rose thought it was prussian or yunker militarism that was at fault, and that countries needed to have finally this tendency rooted out of them. The soviets were very suspicious that the western allies would cut a separate deal with germany and sort of leave them in the lurch. A public pledge for an unconditional surrender help bind all the allies together in a united cause but it meant the war would go on longer.