Immigration is always a hot issue when the economy is weak and jobs are scarce, so it should be no surprise that it has jumped to the top of the political agenda in Europe and the United States. But much of the debate today around these centuries-old themes of us vs. them and newcomer vs. old-timer is missing an essential point: in the age of the Internet, the jet airplane and the multinational company, the very concepts of immigration, citizenship and even statehood are changing.