Gambit, it's all part of the global village concept. Everything is dependent on everyone. If there is unquiet in Libya and the people in Saudi Arabia think they can do the same, the west will not receive oil from Saudi Arabia and therefore oil prices will go up. High oil prices mean inflation in the US which is depend at on Saudi oil. inflation means less money to go around and therefore less money for things like smart phones among other and there is your connection to GLUU.
Japan is one of the largest economies in the world. If Japan gets hurt it affects many Japanese companies that are trading on the American markets and many American companies that do business with Japan. In a case like this a very simple example are the insurance companies that will have to fork over billions of dollars and most of these companies are international.
So all in all, like I said, everything is connected to everything else and therefore when someones farts on one side of the world on the other side they get nervous and one of there first actions is to sell stocks to make sure they have money in their pockets.
I hope my explanation is clear. I thisnk Ieven lost myself in a few places.