Well at least you get some kind of forewarning. Here in Europe we also have earthquakes, but no system even close to the one in Japan. Not to mention buildings that could actually withstand a bigger quake.

Mt. Fuji is "about to erupt" for more than ten years now. The scientist most vocal about it has written two books about it :) Not saying it won't happen, but Mt Fuji is the gentle kind of volcano, so there should be no loss of lifes at least.