Paying double taxes Germany or US

Hi,

My girlfriend and I are planning to work in Taiwan for 2 or 3 years. I am a German citizen and she is US. Someone mentioned to me something about paying taxes in Taiwan and in the US. Is that true, and under what conditions. And does anybody know if it is also true for Germany. We are going to move over there, and we are employed by a Taiwanese company. I hope someone is maybe in a similar situation and can help us out with some information.

Thanks

ratlung