The act of state doctrine is a court-made (common law) doctrine that prohibits U.S. courts from judging the validity of the official acts of a foreign country that take place within that foreign country's borders.
In Michigan, as in other U.S. states, the act of state doctrine is recognized and applied based on federal common law, rather than state statutes. This doctrine holds that U.S. courts will generally not examine or question the validity of public acts performed by a recognized foreign sovereign within its own territory. The rationale behind this doctrine is to avoid conflict with other nations that could arise if U.S. courts were to declare foreign acts invalid. It is rooted in the principles of sovereignty and respect for other nations. However, the doctrine is not absolute and may not apply in certain circumstances, such as when a clear violation of international law is present or when the U.S. has a strong interest in applying its own law. The U.S. Supreme Court and lower federal courts have developed the contours of this doctrine, and while state courts in Michigan may apply it, they do so in accordance with federal case law and the U.S. Constitution.