By George Friedman President Barack Obama has won re-election . However, in addition to all of the constraints on him that I discussed last week, he won the election with almost half the people voting against him. His win in the Electoral College was substantial -- and that's the win that really matters -- but the popular vote determines how he governs, and he will govern with one more constraint added to the others. The question is whether this weakens him or provides an opportunity. That is not determined by his policies but by the strategic situation, which, in my view, gives the United States some much-needed breathing room. The Structure of the International System At the moment, the international system is built on three pillars: the United States, Europe and China . Europe, if it were united, would be very roughly the same size as the United States in terms of economy, population and potential military power. China is about a third the size of the other two econo