Rare Supreme Court holiday activity and ongoing news coverage about special counsel Robert Mueller's investigation has drawn much attention to the enigmatic case of In Re Grand Jury Subpoena. In some regards, the matter is unremarkable, presenting familiar issues of international litigation. Upon further examination, however, the case—about which little is publicly known—may have the potential to expand the authority of United States courts over foreign states and their agencies or instrumentalities.

 In re Grand Jury Subpoena began when a foreign state-owned corporate entity refused to comply with a subpoena issued by the U.S. District Court for the District of Columbia during a grand jury investigation of an undisclosed criminal matter. After the court issued its subpoena, the corporation filed a motion to quash, arguing  that its status as a state-owned corporation ensured protection by foreign sovereign immunity and that compliance with the subpoena would force the corporation to violate the laws of its state of incorporation.

Issues of this sort are hardly novel. Courts routinely grapple with claims of sovereign immunity (including in cases involving subpoenas and other forms of compulsory judicial process) and with claims that compliance with discovery requests would violate foreign law. Indeed, over a century ago, cases like In re Balz and Ex Parte Hirtz addressed claims about a party's foreign immunity affecting their amenability to jurisdiction and other forms of process. (Notably, the court rendered these decisions during a time when common law largely governed the contours of immunity from process, a topic to which we'll return.)