The paper highlights key considerations necessary for the analysis of international tax competition and the desirability of international tax harmonization. The analysis of a Nash—Cournot international tax competition is carried out for (1) competing countries that cannot exercise significant market power in the world economy when setting tax rates, (2) competing countries that incorporate the indirect effect on world prices into the tax design and (3) competing governments that are unable to commit themselves to a preannounced path of tax for the entire future. The discussion is carried out by using basic principles of international taxation under full integration of goods and capital world markets.