A critical impediment to transnational collection of taxes is an old common law rule: the courts of one nation will not enforce the tax laws of another. When first articulated over two hundred years ago, the rule was rational. Countries were engaged in great commercial rivalries and did not wish to assist their international competitors in the collection of revenues.
Jeffery C. Atik,
The Problem of Reciprocity in Transnational Enforcement of Tax Judgments,
Yale J. Int'l L.
Available at: http://digitalcommons.law.yale.edu/yjil/vol8/iss1/7