The Spaniards pointed out that by American law the jurisdiction over a " vessel on the high seas, in time of peace, engaged in a lawful voyage, is, according to the laws of nations, under the exclusive jurisdiction of the State to which her flag belongs; as much so as if constituting a part of its own domain . . . . if such ship or vessel should be forced, by stress of weather, or other unavoidable cause, into the port and under the jurisdiction of a friendly Power, she, and her cargo, and persons on board, with their property, and all the rights belonging to their personal relations as established by the laws of the State to which they belong, would be placed under the protection which the laws of nations extend to the unfortunate under such circumstances . " The Spaniards demanded that the U . S . " apply these proper principles to the case of the schooner " Amistad " ."