L'arbitrage des différends fiscaux en droit international des investissements

One might not think that tax disputes should ordinarily be susceptible to resolution through arbitration. However, recent years have seen the unfolding of an arbitral jurisprudence that puts taxation to the test of international investment law. This thesis describes and evaluates this phenomenon, which raises numerous legally complex and politically delicate issues. These arbitrations are underpinned by a subtle dialectic between investor protection and tax sovereignty of the host State. The pursuit of these two competing goals lays the ground for inevitably thorny questions. Thus, arbitrators are called upon to examine the validity and reach of stabilization guarantees or of tax exemptions granted to foreign investors, or even to determine if a tax measure amounts to a disguised expropriation, a prohibited discrimination, or inequitable treatment, in the sense of an investment treaty. Before resolving these issues, arbitrators must ascertain whether the State has actually and validly consented to submit the exercise of its taxation powers to the scrutiny of a 'private' legal process, and whether the relevant guarantees enshrined in investment treaties apply to the tax measures in question. An analysis of these matters reveals that arbitrators can address questions of tax law without any particular difficulty and that arbitration is a practical method of dealing with these international tax disputes. Moreover, the solutions reached by international arbitral tribunals are, on the whole, satisfying, as arbitrators take into account the particular needs entailed in balancing the public and private interests at stake.