For Japanese households, the coming winter may be even more bitter than usual.

An export ban by South Korea, stemming from disputes over World War II-related issues, could cause shortages and price spikes for kerosene, Bloomberg News has reported. That's a serious threat because about 61 percent of Japan's winter domestic heating is provided by kerosene heaters, which provide instant (if sometimes stinky) heat at the touch of a button.

As with the regular winter gas disputes between Russia and Ukraine, there's no more potent worry when ice grips the landscape than the promise to cut off a nation's supply of heat.