The U.S. Supreme Court case International Longshoremen's Association, Local 1416, AFL-CIO v. Ariadne Shipping Co., Ltd., et al., in 1969 involved a dispute over whether the National Labor Relations Board (NLRB) had jurisdiction to resolve labor disputes involving foreign-flag ships operating in American waters. The International Longshoremen's Association (ILA), an American union representing dockworkers, was accused of violating the National Labor Relations Act by coercing shipping companies into hiring only ILA workers for loading and unloading cargo at Miami ports. The NLRB ruled against the ILA but on appeal, both the Circuit Court and Supreme Court sided with the union stating that Congress did not intend for NLRA to apply to employment practices aboard foreign vessels even if they were temporarily within U.S territorial waters.

In the dissenting opinion for the case of International Longshoremen's Association, Local 1416, AFL-CIO v. Ariadne Shipping Co., Ltd., et al., Justice Harlan disagreed with the majority's interpretation of Section 303(b) of the Labor Management Relations Act. He argued that this section should not be read as a comprehensive regulation on all secondary boycotts but rather as an additional remedy to those already available under common law principles and state statutes. According to him, Congress did not intend to preclude other remedies when it enacted Section 303(b). Furthermore, he contended that there was no evidence in legislative history suggesting such intent from Congress. Therefore, he believed that federal courts should have jurisdiction over cases involving international labor disputes even if they involve secondary boycotts because these are matters affecting commerce and foreign relations which fall within their purview.