This "Tax all the things!" mentality is what got us into the current situation. If a company is going to incur an enormous tax liability by earning the money u

This "Tax all the things!" mentality is what got us into the current situation. If a company is going to incur an enormous tax liability by earning the money under one taxing authority, it will make sense for them to push that revenue to a subsidiary incorporated under a different taxing authority. One with a lower burden. If, for example, the effective tax rate in the US is about 40% and the effective tax rate in Elbonia is 25%, for a sufficiently large corporation, it makes financial sense to incorporate a subsidiary in Elbonia to handle European and Asian business transactions. If the disparity is large enough, it not only makes sense to do so, it starts to border on insanity not to do it. As other have pointed out, these reserves aren't mountains of cash sitting in vaults. It's money that's being lent for interest and invested elsewhere.