In complex environmental disputes the International Court of Justice should utilize its investigatory powers to identify long-term environmental impacts before reaching legal conclusions. Pulp Mills on the River Uruguay highlights the ICJ’s current reluctance to utilize its investigatory powers—instead, the court relies on the parties’ contentious scientific submissions and fails to verify all potential environmental harms. In so doing, the court fails to conform to the international principle of sustainable development. This Comment identifies the Rules of Court and past cases that demonstrate that justices have the power to question expert witnesses and request independent investigation when evaluating questionable or incomplete scientific evidence. Additionally, this Comment argues that such ICJ-ordered independent investigations will bolster growing international support for the principle of sustainable developmen