Germany and Japan are part of the west. Their success was achieved in the busom of the west. After WW2 both were integrated into the west and to this day both are stalwarts of the west.
Currency, any currency is a medium and has no intrinsic value. That comes from what others give it. Meaning when you that paper out how it buys across the world. The reason dollar is dollar is across the globe it puts a smile on peoples faces. You can't replace that anytime soon. Only China might be able to do it in time.