Why Canada’s Terrorism Exception Does Not Violate International Law
May 27, 2025
Like the United States, Canada has an exception in its State Immunity Act (SIA) for state supporters of terrorism. Canada has put Iran and Syria on the list of states against which claims for terrorism may be brought in Canadian courts. Under the SIA, Canadian courts have found Iran liable for shooting down a Ukraine International Airlines flight in 2020 and have recognized and enforced U.S. terrorism judgments against Iran.
In 2023, Iran sued Canada at the International Court of Justice (ICJ), claiming that the SIA’s terrorism exception denies Iran immunity to which it is entitled under customary international law. In a prior case, Iran tried to argue that the U.S. exception for state sponsors of terrorism in the Foreign Sovereign Immunities Act (FSIA) violates international law, but the ICJ held that it lacked jurisdiction over that claim. Iran’s case against Canada provides a chance to test the lawfulness of the U.S. exception as well.
The Debate Back in 2023
Back in 2023, there was a lively debate on this blog and others about the merits of Iran’s argument. Maryam Jamshidi argued that the Canadian and U.S. exceptions violate customary international law because the practice of just two states is not enough to create an exception to immunity. Keshav Somani supported her argument, claiming that the ICJ in Jurisdictional Immunities had adopted a baseline rule of immunity, requiring a general and consistent practice of states to create an exception. Keshav also argued that state-sponsored terrorism is by definition a sovereign act because it can only be done by states. Kelly Adams staked out an intermediate position, arguing that some acts of terrorism may be sovereign acts, whereas others may not be.
While acknowledging Kelly’s point, I responded that (1) acts of terrorism are generally non-sovereign acts because private parties can engage in them; and (2) the baseline for analysis in this area of customary international law is jurisdiction rather than immunity—that is, that a general and consistent practice of states is required to create a rule of immunity rather than to create an exception to immunity.
My Forthcoming Paper
I have now fleshed these arguments out more fully in a paper to be published in the Canadian Yearbook of International Law, a preprint of which is available at SSRN. I will not repeat here all the arguments in the paper. But I will observe that I was pleasantly surprised to find significant support among well-respected scholars for both parts of my argument.
The Test for Non-Sovereign Acts
With respect to the test for non-sovereign acts, Sir Robert Jennings (then a judge on the ICJ) suggested in 1988 that one should “look at the legal nature of the act and ask whether it could have been done by a private person.” A few years later, Dame Rosalyn Higgins (soon to succeed Jennings on the ICJ) phrased the test as “whether an act is one that may be performed by anyone, or only by a sovereign.” And James Crawford, writing the ninth edition of Brownlie’s Principles of Public International Law while he too was sitting on the ICJ, asked simply whether the act is “not unique to the state.” (Citations for each of these quotations may be found in the paper.)
It should be obvious that terrorism and support for terrorism are acts that can be done by private persons. One sometimes hears the counterargument that state-sponsored terrorism is, by definition, something that only states can engage in. But this is tautological. One could as easily say that government contracting is a sovereign activity because, by definition, only sovereigns can engage in it. Accepting this proposition would return us to the days of absolute immunity because one can append “governmental” to anything that a state does and thus, according to this line of argument, render it a sovereign act.
The Proper Baseline
In writing the paper, I also found significant support for the proposition that the proper baseline for analysis is one of jurisdiction rather than immunity. In 1980, Sir Ian Sinclair, then Legal Adviser to the U.K. Foreign and Commonwealth Office, wrote that “one does not start from an assumption that immunity is the norm, and that exceptions to the rule of immunity have to be justified. One starts from an assumption of non-immunity.” Both Jennings and Higgins have expressed similar views. (Again, for citations, see the paper.)
Some have argued that a baseline of immunity may be derived from the principle of sovereign equality, but Crawford has rightly characterized this as “question begging.” States may be equal with respect to many things. States may have an equal right not to be sued in the courts of other states. By the same token, states may have an equal right to exercise jurisdiction. When these rights come into conflict, the principle of sovereign equality does not help us choose which prevails.
Keshev’s blog post, referred to above, pointed to the practice, followed in drafting international conventions and domestic statutes, of stating a general rule of immunity followed by exceptions indicates a baseline of immunity. Certainly, this is state practice, but is it accompanied by the opinio juris needed to establish a rule of customary international law? It seems more likely that this practice reflects drafting convenience than any sense of legal obligation.
In the paper, I look instead to evidence during the transition from the absolute theory of foreign sovereign immunity to the restrictive theory to show that the proper baseline in this area of customary international law is jurisdiction. In 1952, for example, when the United States adopted the restrictive theory, only six other states (out of 77 in the world at that time) had previously done so. One cannot say that six out of 77 constitutes a general and consistent practice of states. If the baseline were really immunity and a general and consistent practice (plus opinio juris) were required to establish exceptions, the United States’ adoption of the restrictive theory would have been in clear violation of international law. But the United States certainly did not think that was true, and so far as I know other countries did not think so either.
Conclusion
There is much more to say about each of these arguments. For readers interested in pursuing them, I refer you to the paper. It will be interesting to hear what Iran and Canada have to say, Iran filed its memorial on October 16, 2024. Canada’s counter-memorial is due October 16, 2025. It is not clear to me whether the United States will participate in some way to defend the lawfulness of its terrorism exception. When the memorials become public, I will try to offer further thoughts.