Secondary boycotts, strikes, and picketing are increasingly common in global industries. When conducted domestically by U.S. workers, such activity has historically been enjoined by courts pursuant to the National Labor Relations Act, which governs collective bargaining agreements in most private sector industries. But collective bargaining in the rapidly globalizing airline industry is regulated under a different statute—the Railway Labor Act—which is not clear regarding the legality of secondary activity. Congress has repeatedly refused to amend the Railway Labor Act to clarify its scope, even as solidarity among the world’s airline workers reaches an all-time high. Consequently, the legality of transnational secondary activity under the Railway Labor Act is uncertain. While courts have generally presumed that U.S. labor laws do not apply extraterritorially, they sometimes reach the opposite conclusion in situations where activity takes place partially in the United States or where U.S. interests are at stake. In determining whether the Railway Labor Act regulates transnational labor organizing, courts ought to apply a balancing approach that takes U.S. interests as well as foreign interests and laws into account.