The U.S. Supreme Court case Buffalo Forge Co. v. United Steelworkers of America, AFL-CIO et al., revolved around a labor dispute in which the union went on strike not over its own contract with the company but to support another striking union at a different branch of the same company (sympathy strike). The question before the court was whether or not such sympathy strikes were prohibited by an existing no-strike clause in their collective bargaining agreement and if they could be enjoined under Section 4(a) of Norris-LaGuardia Act. In a decision delivered by Justice Brennan, it was held that federal courts did not have jurisdiction to issue injunctions against such strikes when they do not involve disputes over terms and conditions covered by ongoing arbitration between employer and employees' representatives as per their collective bargaining agreement. It further clarified that sympathy strikes are only enjoinable if they violate specific no-strike provisions within an active collective bargaining agreement - something absent in this case.

In the dissenting opinion for Buffalo Forge Co. v. United Steelworkers of America, AFL-CIO, Justice William J. Brennan Jr., joined by Justices Byron R. White and Thurgood Marshall, argued that the majority's decision was a departure from established labor law principles and precedent set in previous cases such as Sinclair Refining Co v Atkinson (1962). They contended that an injunction should not have been issued against the union because it did not violate any contractual no-strike obligation during arbitration proceedings; rather, its strike was over separate issues unrelated to ongoing arbitration disputes with Buffalo Forge Company. The dissenters believed this distinction mattered under federal labor laws designed to protect workers' rights to collective action unless explicitly waived in their contracts - which they felt had not occurred here due to ambiguity about what constituted "arbitrable" grievances within said contract language itself.