Offshore financial centres are coming under increasing pressure from both the OECD and the European Union. They are seen by many bureaucrats and politicians in OECD countries as facilitating criminal activities such as laundering drug money as well as tax evasion and tax avoidance by residents of high‐tax welfare states. While there are good reasons for nation states to cooperate to suppress criminal activity, this is not true in relation to tax competition. The notion that by engaging in ‘harmful’ tax competition, offshore financial centres are damaging the legitimate interests of OECD nations has no sound foundation in economic theory. Competition in tax matters is beneficial and world welfare enhancing. Governments of offshore financial centres serve their own and the world's interests by providing zero or low tax environments for global business and investment and they are right to insist that treaties on criminal matters should not be used to enforce other countries' tax claims.