International investment law, and particularly investor state dispute settlement (ISDS) is currently the subject of many heated debates, from the fairness of bilateral investment treaties, to the lack of precedent in ISDS, to the impartiality of arbitrators. This article examines national judicial review of international investment arbitral awards in the context of U.S. domestic law, focusing on evident partiality and the appropriate standard of deference to be applied to such awards, particularly in the case where challenges to arbitrator integrity were denied at the arbitration stage. National courts are not the ideal fora for adjudicating challenges to ISDS awards, as evidenced by differing standards of deference across jurisdictions and the lack of familiarity with international treaties and international rules of arbitration. Addressing the problem at its root, namely through amending international rules of arbitration or by creating additional levels of international review would be more effective. The problem of arbitrator partiality in ISDS is reflective of systemic problems. This article argues that the issues of interpretation arising in reviewing ISDS awards before domestic courts suggest that reform of the ISDS system would be a more effective means of safeguarding party interests from arbitrator conflict of interest or corruption. This article builds on the standard of deference established by the Supreme Court in BG Group, focusing on the Argentina v. AWG Group case that was decided by the D.C. Circuit Court of Appeals in July 2018. In reviewing the Argentina v. AWG Group case, the article highlights some of the challenges in having domestic courts review ISDS awards. At the same time, the article argues that while a high level of deference to international arbitration awards is usually desirable, the standard of review with respect to ISDS claims should be clarified by U.S. courts as deference is not always the correct standard. Where the integrity of the arbitral tribunal itself is in question, that deference should be set aside in favor of closer review. Conflicts of interest that might elsewhere be viewed as significant enough to disqualify arbitrators from participating in arbitrations are viewed as commonplace in international investment arbitration and considered an inherent part of the system. This should not be the case.