War Powers, Red Lines, and Credibility

Last fall, during the debate on airstrikes in Syria, commentators argued that the United States needed to act in order to preserve the credibility of American threats. If the “red line” that President Obama announced a year earlier wasn’t enforced, the argument went, dictators would be able to act with impunity. Interestingly, political scientists have offered serious critiques of credibility arguments, demonstrating not only that they are logically problematic but also that there is little historical support for them.  Some foreign policy bloggers pointed this out during the Syria debate. But the credibility argument wasn’t a big part of the legal debate over Syria. (One notable exception was Lawfare’s own Wells Bennett.) Over at the Harvard Law Review Forum, I have a new essay arguing that constitutional lawyers should be troubled by the political science research on credibility in foreign policy because “credibility” has migrated from foreign policy debates into the law of war powers. In a series of opinions since the end of the Cold War, the Office of Legal Counsel has argued that the “credibility” of the UN Security Council is a “national interest” that can justify presidential authority to use force without prior congressional approval. The result is that preserving the “credibility” of the UN is a contributing---and perhaps even sufficient (OLC is unclear on sufficiency)---reason for the President to use force without prior congressional approval. This is problematic because the political science research, basic reasoning about credibility, and concerns about future OLC expansion of the “credibility” category all suggest that credibility arguments are a weak policy foundation for unilateral presidential war powers. Ganesh Sitaraman is an Assistant Professor of Law at Vanderbilt Law School.