Act of state doctrine
The Act of State Doctrine states that every sovereign state is bound to respect the independence of every other sovereign state, and the courts will not sit in judgment of another government's acts done within its own territory.
The doctrine is not required by international law (neither customary international law nor treaty law), but it is a principle recognized and adhered to by United States federal and state courts. In the United States, the rationales for the doctrine include respect for other nations' sovereignty and protection of the US Executive's prerogative in foreign affairs, both of which may be frustrated by a decision issuing from U.S. courts.