It is trite law that international arbitration is subject to control. When two parties agree to arbitrate a dispute, the resulting arbitral award will be recognized as producing legal effects only if it fulfills the conditions set forth in the applicable arbitration framework. This is due to the dual foundation of arbitration in party autonomy on the one hand and the applicable arbitration framework on the other.1 If one turns to the question of who is tasked to exercise this control, the answer is not straightforward. At first glance, it appears as if national courts are the sole guardians to watch over arbitral awards. This view reflects a public–private divide between arbitral tribunals who as private actors render an arbitral award, which is then subject to control by a national court as a public actor.