This section is from the book "The Constitutional Law Of The United States", by Westel Woodbury Willoughby. Also available from Amazon: Constitutional Law.
From the cases already cited, it follows that determinations by the political departments as to existence of a status of independence, or of war, or of belligerency, are not reviewable by the courts.
In United States v. Palmer10 Marshall declares: "Those questions which respect, the rights of a part of a foreign empire which asserts or is contending for its independence, and the conduct which must be observed by the courts of the Union towards the subjects of such section of an empire who may be brought before the tribunals of this country . . . are generally rather political than legal in their character. They belong more properly to those who can declare what the law shall be; who can place the nation in such a position with respect to foreign powers as to their own judgment shall appear wise, to whom are entrusted all its foreign relations, than to that tribunal whose power as well as duty is confined to the application of the rule which the legislature may prescribe for it. In such contests a nation may engage itself with the one party or the other - may observe absolute neutrality -or may make a limited recognition of it. The proceedings in the court must depend so entirely on the course of the government that it is difficult to give a precise answer to questions which do not refer to a particular nation. It may be said, generally, that if the government remains neutral, and recognizes the existence of a civil war, its courts cannot consider as criminal those acts of hostility which war authorizes, and which the new government may direct against the enemy. To decide otherwise, would be to determine that the war prosecuted by one of the parties was unlawful, and would be to array the nation to which the court belongs against that party. This would transcend the limits prescribed to the judicial department." 11
9 137 U. S. 202; 11 Sup. Ct. Rep. 80; 34 L. ed. 691. 10 3 Wh. 610; 4 L. ed. 471.
Of course the courts of one country are not bound by the decisions of another country as to the territorial extent of jurisdiction of that country, or indeed as to any question of international law and right. In Rose v. Himely12 the court, speaking through the mouth of Marshall, says: "Of its own jurisdiction, so far as depends on municipal rules, the court of a foreign nation must judge, and its decisions must be respected. But if it exercise a jurisdiction which, according to the law of nations, its sovereign could not confer, however available its sentences may be within the dominions of the prince from whom the authority is derived, they are not regarded by foreign courts. This distinction is taken upon this principle, that the law of nations is the law of all tribunals in the society of nations, and is supposed to be equally understood by all. Thus the sentence of a court sitting in a neutral territory, and instituted by a belligerent, has been declared not to change the property it confessed to condemn; and thus the question whether a prize court sitting in the country of the captor could condemn property lying in a neutral port, has been fully examined, and although the jurisdiction of the court in such case was admitted, yet no doubt appears to have been entertained of the propriety of examining the question, and deciding it according to the practice of the nations."
11 In The Divina Pastora (4 Wh. 52; 4 L. ed. 512) Marshall again says: "The decision at the last term, in the case of the United States v. Palmer, establishes the principle that the government of the United States, having recognized the existence of a civil war between Spain and her colonies, but remaining neutral, the courts of the Union are bound to consider as lawful those acts which war authorizes, and which the new governments in South America may direct against their enemy." See also The Santissima Trinidad. 7 Wh. 283; 5 L. ed. 454, and Kennett v. Chambers, 14 How. 38; 14 L. ed. 316.
12 4 Cr. 241; 2 L. ed. 608.