concurring.
I concur in the result.
I do not think that “martial law,” as used in § 67 of the Hawaiian Organic Act, is devoid of meaning. This Court has had occasion to consider its scope and has pointed out that martial law is the exercise of the power which resides in the executive branch of the Government to preserve order and insure the public safety in times of emergency, when other branches of the Government are unable to function, or their functioning would itself threaten the public safety. Luther v. Borden, 7 How. 1, 45. It is a law of necessity to be prescribed and administered by the executive power. Its object, the preservation of the public safety and good order, defines its scope, which will vary with the circumstances and necessities of the case. The exercise of the power may not extend beyond what is required by the exigency which calls it forth. Mitchell v. Harmony, 13 How. 115, 133; United States v. Russell, 13 Wall. 623, 628; Raymond v. Thomas, 91 U. S. 712, 716; Sterling v. Constantin, 287 U. S. 378, 400, 401. Any doubts that might be enter-*336tamed that such is the true limit of martial law in this case are put at rest by § 67 of the Hawaiian Organic Act, which, “in case of rebellion or invasion, or imminent danger thereof,” authorizes martial law only “when the public safety requires it ...”
The Executive, has broad discretion in determining when the public emergency is such as to give rise to the necessity of martial law, and in adapting it to the need. Cf. Hirabayashi v. United States, 320 U. S. 81. But executive action is not proof of its own necessity, and the military’s judgment here is not conclusive that every action taken pursuant to the declaration of martial law was justified by the exigency. In the substitution of martial law controls for the ordinary civil processes, “what are the allowable limits of military discretion, and whether or not they have been overstepped in a particular case, are judicial questions.” Sterling v. Constantin, supra, 401.
I take it that the Japanese attack on Hawaii on December 7, 1941, was an “invasion” within the meaning of § 67. But it began and ended long before these petitioners were tried by military tribunals in August 1942 and February 1944. I assume that there was danger of further invasion of Hawaii at the times of those trials. I assume also that there could be circumstances in which the public safety requires, and the Constitution permits, substitution of trials by military tribunals for trials in the civil courts. But the record here discloses no such conditions in Hawaii, at least during the period after February, 1942, and the trial court so found. After closing places of amusement, and after closing the civil courts on December 8, 1941, the military authorities, on December 24, 1941, ordered places of amusement to be opened. On January 27,1942, they permitted the courts to exercise their normal functions except as to jury trials and the issuance of writs of habeas corpus. On February 4, 1942, they authorized the sale of liquor at bars.
*337The full record in this case shows the conditions prevailing in Hawaii throughout 1942 and 1943. It demonstrates that from February 1942 on, the civil courts were capable of functioning, and that trials of petitioners in the civil courts no more endangered the public safety than the gathering of the populace in saloons and places of amusement, which was authorized by military order. I find nothing in the entire record which would fairly suggest that the civil courts were-unable to function- with their usual efficiency at the times these petitioners were tried, or that their trial by jury in a civil court would have endangered good order or the public safety. The Governor of Hawaii and the Chief Justice of the Hawaiian supreme court testified to the contrary. The military authorities themselves testified and advanced no reason which has any bearing on public safety or good order for closing the civil courts to the trial of these petitioners, or for trying them in military courts. I can only conclude that the trials and the convictions upon which petitioners are now detained, were unauthorized by the statute, and without lawful authority.
We have no occasion to consider whether the arrest and detention of petitioners by the military authorities, pending their delivery to the civil authorities for trial, would have been lawful. The judgment of the circuit court of appeals should be reversed and the petitioners discharged from custody forthwith.