A nation may use all the methods permissible in a war against a foreign power, in putting down a rebellion on the part of a portion of its own subjects.

1 Davis on International Law, page 274.

The question was ably argued by the Supreme Court of the United States in the Prize Cases,2 the decision in which case was in part as follows:

"There are certain prepositions of law which must necessarily affect the ultimate decision of these cases, and many others, which it will be proper to discuss and decide before we notice the special facts peculiar to each.

"They are: 1st. Had the President a right to institute a blockade of ports in possession of persons in armed rebellion against the government, on the principles of international law, as known and acknowledged among civilized states?

"2nd. Was the property of persons domiciled or residing within those states a proper subject of capture on the sea as "enemies' property?"

"1. Neutrals have a right to challenge the existence of a blockade de facto, and also the authority of the party exercising the right to institute it. They have the right to enter the ports of a friendly nation for the purposes of trade and commerce, but are bound to recognize the rights of a belligerent engaged in actual war to use this mode of coercion, for the purpose of subduing the enemy.

"That a blockade de facto actually existed, and was formally declared and notified by the President on the 27th and 30th of April, 1861, is an admitted fact in these cases.

"That the President, as the Executive Chief of the Government and Commander-in-Chief of the Army and Navy, was the proper person to make such notification, has not been, and cannot be disputed.

"The right of prize and capture has its origin in the jus belli, and is governed and adjudged under the law of nations. To legitimate the capture of a neutral vessel or property on the high seas, a war must exist de facto, and the neutral must have a knowledge or notice of one of the parties belligerent to use this mode of coercion against a port, city, or territory, in possession of the other.

2 2 Black, 635.

"Let us inquire whether, at the time this blockade was instituted, a state of war existed which would justify a resort to these means of subduing the hostile force.

"The parties belligerent in a public war are independent nations. But it is not necessary, to constitute war, that both parties should be acknowledged as independent nations or sovereign states. A war may exist where one of the belligerents claims sovereign rights as against the other.

"Insurrection against a government may or may not culminate in an organized rebellion, but a civil war always begins by insurrection against the lawful authority of the government. A civil war is never solemnly declared; it becomes such by accidents, the number, power, and organization of the persons who originate and carry it on. When the party in rebellion occupy and hold in a hostile manner a certain portion of territory; have declared their independence; have cast off their allegiance; have organized armies; have commenced hostilities against their former sovereign, the world acknowledges them as belligerents, and the contest a war. They claim to be in arms to establish their liberty and independence, in order to become a sovereign State, while the sovereign party treats them as insurgents and rebels who owe allegiance, and who should be punished with death for their treason.

"The laws of war, as established among nations, have their foundation in reason, and all tend to mitigate the cruelties and misery produced by the scourge of war. Hence the parties to a civil war usually concede to each other belligerent rights. They exchange prisoners, and adopt the other courtesies and rules common to public or national wars.

"'A civil war,' says Vattel, 'breaks the bands of society and government, or at least suspends their force and effect; it produces in the nation two independent parties, who consider each other as enemies and acknowledge no common judge. Those two parties, therefore, must necessarily be considered as constituting, at least for a time, two separate bodies, two distinct societies. Having no common superior to judge between them, they stand in precisely the same predicament as two nations who engage in a contest and have recourse to arms.

"'This being the case, it is very evident that the common laws of war - those maxims of humanity, moderation, and honor - ought to be observed by both parties in every civil war. Should the sovereign conceive he has a right to hang up his prisoners as rebels, the opposite party will make reprisals, etc., etc.; the war will be cruel, horrible, and every day more destructive to the nation.'

"As a civil war is never publicly proclaimed, eo nomine, against insurgents, its actual existence is a fact in our domestic history which the court is bound to notice and know.

"The true test of its existence, as found in the writings of the sages of the common law, may thus be summarily stated: 'When the regular course of justice is interrupted by revolt, rebellion, or insurrection, so that the courts of justice cannot be kept open, civil war exists and hostilities may be prosecuted on the same footing as if those opposing the government were foreign enemies invading the land.'

"By the Constitution, Congress alone has the power to declare a national or foreign war. It cannot declare war against a State, or any number of states, by virtue of any clause in the Constitution. The Constitution confers on the President the whole executive power. He is bound to take care that the laws be faithfully executed. He is Commander-in-Chief of the Army and Navy of the United States, and of the militia of the several states when called into the actual service of the United States. He has no power to initiate or declare a war either against a foreign nation or a domestic State. But by the Acts of Congress of February 28, 1795, and 3rd of March, 1807, he is authorized to call out the militia and use the military and naval forces of the United States in case of invasion by foreign nations, and to suppress insurrection against the government of a State or of the United States.