In the case of W. S. Kirkpatrick & Co., Inc., et al. v. Environmental Tectonics Corp., International, 1989, the U.S Supreme Court ruled that courts in the United States cannot judge the validity of actions by foreign governments within their own territories under the act of state doctrine. The dispute arose when Environmental Tectonics Corporation (ETC) sued W.S Kirkpatrick & Co for bribing Nigerian officials to secure a contract which ETC claimed it should have won due to its lower bid price and superior technical proposal. However, Justice Antonin Scalia delivered an unanimous opinion stating that even if bribery did occur, it would not be appropriate for American courts to invalidate Nigeria's decision as this would interfere with diplomatic relations between countries.

In the dissenting opinion for W. S. Kirkpatrick & Co., Inc., et al. v. Environmental Tectonics Corp., International, Justice Brennan, joined by Justices Marshall and Blackmun, argued that the act of state doctrine should not be applied to this case as it was a commercial dispute between two private parties rather than an issue involving foreign policy or relations with another sovereign nation. They contended that applying the act of state doctrine in such cases would unnecessarily extend its scope beyond its original purpose - to prevent courts from passing judgment on acts committed by foreign governments within their own territories - and could potentially interfere with Congress's power to regulate commerce under Article I of the Constitution. The dissenting justices believed that whether bribery occurred is a factual question which can be determined without questioning Nigeria's sovereignty or violating international law principles.