For the Japanese it's more of the case of the United States being overstretched in its military obligations

Also the choice of the American government to build supercarriers over constructing smaller carriers and destroyers

Has meant the United States sea power can not be where it needs to be

So the USA is needed the Japanese and others to start acting as their deputies in certain regions of the world

The British did the same with the Japanese in the run-up to world War II in the British and Japanese Alliance of 1902

Because the British needed a deputy in East Asia whilst Britain was planning and preparing for a Great War in Europe