International investment law has been much criticized as an undue restraint upon the regulatory sovereignty of states, although paradoxically, under the law of the WTO, the sanction upon the losing state of having to withdraw an offending measure weighs more heavily upon states than the duty to make financial compensation. This paper considers the elements of commonality between international trade law and international investment law, and asks whether the growing convergence of these two regimes should lead to convergence of dispute settlement procedures under the World Trade Organization’s Dispute Settlement Understanding and investor-state arbitration under bilateral investment agreements.