Many international law scholars purport that treaties are the most effective and binding source of international law. However, the efficacy of multilateral treaties may be exaggerated, as demonstrated by minimal penalties for noncompliance, particularly for strong states, and the United States’ absence from and self-interested interpretation of various treaties.
The promotion of credible commitment is held as an essential benefit of treaties; proponents argue that treaties raise the cost of noncompliance more effectively than informal methods and are unique in showing the seriousness of a party to a commitment. These contentions lose some force after investigating three enforcement mechanisms for treaty breaches, and the lack of negative impacts thereof.
First, while the Vienna Convention on the Law of Treaties (VCLT) Article 60 allows for termination or suspension of a treaty in the event of material breach, the likelihood of that termination occurring is minimal, especially for certain types of treaties. For human rights, nuclear non-proliferation, or environmental treaties, termination would undermine the global stability and norms that the parties entered into the treaty to protect. States’ commitment to the International Covenant on Civil and Political Rights, a key human rights treaty, has not wavered despite numerous breaches, even as recent as June 2020 after a United Nations’ report outlined the Philippines’ grave human rights violations.
Second, strong states are less likely to face retaliation or penalties as a result of treaty violation. For these states, breach does not typically threaten reputational damage severe enough to encourage compliance, nor do they fear reciprocal sanctions, political pressure, or other retorsions and countermeasures as much because of their position as economic and political powerhouses. Strong states often act out of self-preservation and self-aggrandizement, reacting to power dynamics instead of legal obligations or fear of penalty: according to realist Charles Krauthammer, treaties are meaningless “when dealing with countries for which law of any kind is a mere instrument, infinitely adaptable to the requirements of power.” Other enforcement mechanisms, such as internal domestic pressure and shaming by NGOs, are not unique to treaties and are just as influential for breaches of customary international law (CIL) or unilateral statements.
Third, the idea that treaty breach can trigger legal actions in court against the violator is actually limited in practice, as there is not always guarantee of jurisdiction. States face binding legal repercussions before the International Court of Justice (ICJ) under three situations of contentious jurisdiction, which are often avoided by states. The ICJ has jurisdiction over leading international actors like the U.S., Russia, and China only if they signed a prior treaty agreeing to refer disputes to the court; the U.S. has further limited this legal accountability. It announced in October 2018 that it would withdraw from the Optional Protocol and Dispute Resolution to the Vienna Convention on Diplomatic Relations, which granted ICJ jurisdiction. Ambassador Bolton justified this by referring to President Reagan’s withdrawal from the Optional Compulsory Jurisdiction of the ICJ under Article 36(2) of the ICJ statute and President Bush’s withdrawal from the Optional Protocol to the Vienna Convention on Consular Relations, two additional ways the U.S. has lessened its ability to be held liable. Even when the ICJ or other third-party mechanisms are available options, states can be reluctant to take their disputes there. For these reasons, lack of definite review before a court minimizes the threat of being held accountable for breach, thereby negating much of a treaty’s meaningfulness in promoting credible commitment and compliance. While multilateral treaties strive to create uniform, widespread agreement and enforceability, perhaps it is instead CIL – which emerges over time as binding upon all states without having to opt-in to legal review – that accomplishes that goal, enabling potential accountability for any state’s violation of the law.
In addition to the lack of repercussions for treaty noncompliance, a look at the U.S.’s absence and withdrawal from various multilateral agreements suggests that treaties may not be as significant or effective as frequently argued. The U.S. has not signed or ratified several key international treaties; it is not party to the VCLT or the United Nations Convention on the Law of the Sea, but generally accepts their guidelines as binding under CIL. This begs the question: Is codification via treaty necessary for adherence and enforcement, or can CIL be enough?
Additionally, the Trump administration has recently withdrawn from numerous treaties. In May 2020, the U.S. announced its intentions to withdraw from the 1992 Open Skies Treaty (OST), which was formed after the Cold War to promote trust between the U.S. and Russia and allows parties to conduct unarmed surveillance flights in each other’s air space. The very premise of this treaty has eroded. The U.S. accused Russia of treaty breach and is now pulling out, despite other countries expressing both continued commitment to the agreement and worry regarding U.S. withdrawal. So another question arises: How effective is a treaty like the OST in its objective to create a binding foundation for trust if irrational leaders can undermine just that, seemingly without concern for the other parties or for global stability?
Treaties’ efficacy is also called into question by the U.S.’s wielding of economic power to cripple still-intact treaties. In 2018, the U.S. withdrew from the Joint Comprehensive Plan of Action (JCPOA) – better known as the Iran nuclear deal – which allowed for the easing of economic sanctions in exchange for Iran restricting its nuclear program. Believers in treaties’ infallible strength would likely have envisioned that the other P5+1 members could continue adhering to the JCPOA’s conditions, at least to a degree. However, the U.S. imposed secondary sanctions on any government that traded with Iran, using its “domination of financial markets” to “bull[y] other countries into capitulating.” Another question yet: Can treaties be touted as binding and successful mechanisms if one powerful, renegade state can threaten the entire agreement through economic force?
For treaties that it is party to, the U.S. leans heavily on constitutional doctrine to establish its own rules for treaty interpretation and adherence, doing so without great repercussions from the international community. The U.S. has decided that extradition, tax, and bilateral investment treaties are self-executing, but all other treaties are not. Another example of the U.S.’s subjective, self-interested approach is its disregard of VCLT Article 27 by frequent adherence to the later-in-time rule, stipulating that a federal statute can supersede a preceding international treaty. These unitary decisions allow the U.S. to evade responsibility for what would otherwise be treaty violations.
While treaties’ importance may be overstated, they still hold a meaningful function in international law and could be adapted for greater value. The U.S. – and other strong states – adhere to the majority of their treaty obligations, indicating respect for international law. Compliance could be improved by codifying a more systematic approach to handling breaches. Treaty drafters might consider requirements that specify how states must take action to penalize violators. International Law Commission Articles 40 and 41 require states to act in the event of particular violations regarding state responsibility. Adopting a similar method and creating mandatory responses to certain treaty violations could increase compliance, in particular by strong states like the U.S., by establishing a more credible fear of penalty.
 See, e.g., Andrew T. Guzman, International Law: A Compliance Based Theory 53–54 (University of California at Berkeley School of Law, Working Paper No. 47, 2001).
 See, e.g., Charles Lipson, Why Are Some International Agreements Informal?, 45 Intl.Org. 495, 508–12 (1991).
 Vienna Convention on the Law of Treaties art. 60, opened for signature May 23, 1969, 1155 U.N.T.S. 331 (entered into force Jan. 27, 1980).
 See Jeffrey L. Dunhoff, Monica Hakimi, Steven R. Ratner & David Wippman, International Law: Norms, Actors, Process: A Problem-Oriented Approach, (5th ed. forthcoming 2020).
 See Press Release, United Nations Human Rights Office of the High Comm’r, Philippines: UN Human Rights Experts Renew Call for an On-The-Ground Independent, Impartial Investigation (June 25, 2020) https://www.ohchr.org/EN/NewsEvents/Pages/DisplayNews.aspx?NewsID=25999&LangID=E.
 See, e.g., Eric A. Posner & Alan O. Sykes, Efficient Breach of International Law: Optimal Remedies, ‘Legalized Noncompliance,’ and Related Issues, 110 Mich. L. Rev. 243, 268–69 (2011).
 See Monica Hakimi, Why Should We Care About International Law?, 118 Mich. L. Rev. 1283, 1283 (2020) (writing that realist theorists believe “states, especially powerful states, can just violate the law; because the international legal system lacks centralized enforcement agents, any repercussions for the violation will be determined not by law but by the participants’ own interests and power relations”).
 Charles Krauthammer, The Curse of Legalism: International Law? It’s Purely Advisory, The New Republic, 44–46, 50 (1989).
 See, e.g., Katrin Kinzelbach & Julian Lehmann, Can Shaming Promote Human Rights? Publicity in Human Rights Foreign Policy 5 (2015), https://www.gppi.net/media/Kinzelbach_Lehmann_2015_Can_Shaming_Promote_Human_Rights.pdf. (finding that “shaming can have a positive impact on the human rights situation in targeted states…. Shaming works for economically weak and strong states alike….”)
 See Statute of the International Court of Justice, art. 36.
 David A. Koplow, Indisputable Violations: What Happens When the United States Unambiguously Breaches a Treaty, 37 Fletcher F. World Aff. 53, 54–55 (2013).
 John Bolton, Ambassador to the United Nations, Remarks on the Withdrawal from the Optional Protocol on Dispute Resolution to the Vienna Convention on Diplomatic Relations (Oct. 3, 2013), https://americanrhetoric.com/speeches/johnboltonviennaoptionalprotcolsuswithdrawl.htm.
 See Anais Kedgley Laidlaw & Shaun Kang, The Dispute Settlement Mechanisms in Major Multilateral Treaties 60 (NUS Law Working Paper Series 2018/028, 2018), https://ssrn.com/abstract=3269134; see also, e.g., Research Handbook on Intellectual Property and Climate Change 109 (Joshua D. Sarnoff ed., 2016).
 The U.S. is the only UN member state not party to the UN Convention on the Rights of the Child and one of four UN states to not ratify the Kyoto Protocol; it has never ratified the International Labor Convention, International Covenant on Economic, Social, and Cultural Rights, The Convention on the Elimination of All Forms of Discriminations Against Women, and many others. Under President Trump, the U.S. decided not to join the U.N. Arms Trade Treaty or the Trans-Pacific Partnership.
 See Julie Franki, Seize the Sea: The Territorial Conflict Between the United States and China Over Military Operations in the South China Sea, 31 Emory Int’l L. Rev. 1021, 1023 (2017) (stating that the U.S. has accepted UNCLOS as CIL and is thus bound by it); Vienna Convention on the Law of Treaties, U.S. Department of State, https://2009-2017.state.gov/s/l/treaty/faqs/70139.htm (“The United States considers many of the provisions of the Vienna Convention on the Law of Treaties to constitute customary international law on the law of treaties.”)
 Hasan Dudar & Deirdre Shesgreen, Trump’s Long List of Global Trade Deals, Agreements Exited or Renegotiated, USA Today (Nov. 21, 2018, 8:08 AM), https://www.usatoday.com/story/news/2018/11/21/donald-trump-foreign-policy-iran-nafta-russia-mexico-canada-trade/1732952002/.
 It is important to note that the reason for the U.S.’s withdrawal was Russia’s purported violations of the OST, which is a negative response to treaty noncompliance in contrast to that which was discussed earlier.
 Bonnie Jenkins, A Farewell to the Open Skies Treaty, and an Era of Imaginative Thinking, Brookings (June 16, 2020), https://www.brookings.edu/blog/order-from-chaos/2020/06/16/a-farewell-to-the-open-skies-treaty-and-an-era-of-imaginative-thinking/.
 Aaron Mehta & Lorne Cook, European States Vow to Stay in Open Skies Treaty Despite US Exit, Defense News (last updated May 22, 2020, 12:24 PM), https://www.defensenews.com/global/europe/2020/05/22/eu-states-vow-to-respect-open-skies-treaty-despite-us-plan-to-exit/.
 See NATO Allies, Other Nations Urge US Not to Withdraw from Open Skies Accord, France 24 (May 21, 2020, 20:16), https://www.france24.com/en/20200521-us-to-withdraw-from-open-skies-accord-in-trump-s-latest-treaty-pullout.
 See Mark Landler, Trump Abandons Iran Nuclear Deal He Long Scorned, N.Y. Times (May 8, 2018) https://www.nytimes.com/2018/05/08/world/middleeast/trump-iran-nuclear-deal.html.
 Peter Ford, Power Shift: How America’s Retreat Is Reshaping Global Affairs, The Christian Science Monitor (June 26, 2020), https://www.csmonitor.com/World/2020/0626/Power-shift-How-America-s-retreat-is-reshaping-global-affairs.
 See Detlev F. Vagts, The United States and its Treaties: Observance and Breach, 95 Am. J. Int’l L. 313, 313 (2001) (U.S. leaders have “verbalized the idea that the later-in-time rule is the final answer and that the binding effect of international law carries little weight”).
 See Medellín v. Texas, 552 U.S. 491, 546–51 (2008) (Breyer, J., dissenting) (illuminating the problem of the inconsistency regarding U.S. courts’ determinations about self-execution).
 The Cherokee Tobacco, 78 U.S. (11 Wall.) 616 (1870).
 Vagts, supra, at 331–33.
 International Law Commission, arts. 40–41.
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