Greg Mankiw observes a fundamental split on tax policy, reflecting an underlying split in political philosophy:
If you think it is the job of government to take from Peter to pay Paul, and if Peter can move around the globe, then you need international tax cooperation. Otherwise, some countries will become nations of Peters, leaving all the Pauls to fend for themselves. On the other hand, if you think that the main job of government is to facilitate voluntary exchange by protecting property rights, rather than re-slicing the economic pie as it sees fit, then tax competition is a good check against excessive interventionism. In other words, are you more worried about too little government or too much?