Comity refers to the willingness of one court or department of government to respect the rules or decisions of another or to grant it some privilege or favor. Sovereignty is the supreme power to govern over an independent state or nation. Sovereign immunity protects foreign governments from lawsuits when they are acting as a political entity, although not when a government agency enters the commercial field to perform essentially private functions. The Act of State doctrine is a principle of domestic law (not international law) that prohibits the courts of one country from inquiring into the validity of the legislative or executive acts of another country.