The Supreme Court case of Stephen P. Crosby, Secretary of Administration and Finance of Massachusetts, et al., v. National Foreign Trade Council in 1999 revolved around a Massachusetts law that restricted the state from doing business with companies conducting business with Burma (Myanmar). The National Foreign Trade Council challenged this law arguing it interfered with the federal government's ability to regulate foreign affairs. The Supreme Court unanimously ruled in favor of the National Foreign Trade Council stating that under the Supremacy Clause, states cannot interfere with federal government’s authority over foreign policy. Therefore, they found Massachusetts' law unconstitutional because it undermined Congress's intent to limit economic sanctions against Burma to specific actions enumerated by federal statute.

In the dissenting opinion for Crosby v. National Foreign Trade Council, Justice Clarence Thomas argued that Massachusetts' law banning state entities from buying goods or services from companies doing business with Burma did not infrally interfere with federal foreign policy. He contended that the Supremacy Clause of the Constitution only preempts state laws when they conflict with a valid federal law and in this case, he saw no such conflict. According to him, both Massachusetts’ law and Federal Government's sanctions aimed at pressuring Burma into improving its human rights record; thus they shared common objectives rather than being contradictory. Furthermore, he believed it was inappropriate for courts to invalidate a state law based on potential interference with executive branch negotiations as it could potentially undermine states' ability to express their own policies within constitutional limits.