comity of nations
“Until 1952, the United States generally afforded foreign sovereigns absolute immunity from the jurisdiction of the courts, including complete immunity from execution. Unlike state or federal sovereign immunity, foreign sovereign immunity does not derive from the constitution. Foreign sovereign immunity instead derives from concerns of grace and comity between nations. As a result, the Supreme Court regularly deferred to the Executive Branch in determining whether to take jurisdiction over a case concerning a foreign sovereign. The Executive was in a better position to anticipate the foreign relations consequences of subjecting a foreign state to suit in a U.S. court. Under the theory of absolute sovereign immunity, the Executive would regularly recommend that courts decline to take jurisdiction over any case against a foreign sovereign.” J. Garza, Connecticut Bank of Commerce v. Republic of Congo, 309 F.3d 240, 251 (5th Cir. 2002).