28 U.S.C. § 1603(d) (2010) (Title 28—Chapter 97: Jurisdictional Immunities of Foreign States)
For purposes of this chapter [28 U.S.C. §§ 1602 et seq.]—
(d) A "commercial activity" means either a regular course of commercial conduct or a particular commercial transaction or act. The commercial character of an activity shall be determined by reference to the nature of the course of conduct or particular transaction or act, rather than by reference to its purpose.