Three objectives determine this project. First disclose the macroeconomic and political reasons behind the Belgian tax treaty policy.  Explanations remain rather technical, whereas in France and the Netherlands, more explicit treaty policies appear. Second confront the Belgian tax treaty network with Belgium's policy on foreign trade and/or development cooperation. Besides a common European focus, Belgium focuses on the opening of external markets to stimulate sustainable growth, job creation and respect for human rights, attention for ecological and digital evolutions, as well as the integration of developing countries. The potential of tax treaties for these aims remains underrecognized. The last objective looks for technical improvements in the treaty negotiation procedures. To be effective as a policy instrument, the current Belgian average time of ratification of a tax treaty is inappropriately long.. Best practices from other administrations should support facilitations.