Anthony Kennedy

“ These structural differences between the military commissions and courts-martial—the concentration of functions, including legal decisionmaking, in a single executive official; the less rigorous standards for composition of the tribunal; and the creation of special review procedures in place of institutions created and regulated by Congress—remove safeguards that are important to the fairness of the proceedings and the independence of the court. Congress has prescribed these guarantees for courts-martial ”

“ If the military commission at issue is illegal under the law of war, then an offender cannot be tried "by the law of war" before that commission.
The Court is correct to concentrate on one provision of the law of war that is applicable to our Nation's armed conflict [p. 642] with al Qaeda in Afghanistan and, as a result, to the use of a military commission to try Hamdan. Ante, at 629–633; see also 415 F.3d 33, 44 (CADC 2005) (Williams, J., concurring) . That provision is Common Article 3 of the four Geneva Conventions of 1949. ”

“ I likewise see no need to address the validity of the conspiracy charge against Hamdan—an issue addressed at length in Part V of Justice Stevens' opinion and in Part II–C of Justice Thomas' dissent. See ante, at 600–613; post, at 689–704. In light of the conclusion that the military commissions at issue are unauthorized, Congress may choose to provide further guidance in this area. Congress, not the Court, is the branch in the better position to undertake the "sensitive task of establishing a principle not inconsistent with the national interest or with international justice." ”

“ The Court of Criminal Appeals functions as the military's intermediate appeals court; it is established by the Judge Advocate General for each Armed Service and composed of appellate military judges. R. C. M. 1203; 10 U.S.C. §866. This is another means in which, by structure and tradition, the court-martial process is insulated from those who have an interest in the outcome of the proceedings.
Finally, in addition to these powers with respect to the presiding officer, the Appointing Authority has greater flexibility in appointing commission members. ”

“ Congress' chosen language, then, is best understood to allow the selection of procedures based on logistical constraints, the accommodation of witnesses, the security of the proceedings, and the like. Insofar as the " [p] retrial, trial, and post-trial procedures" for the military commissions at issue deviate from court-martial practice, the deviations must be explained by some such practical need. ”

“ Against the background of these significant powers for the Appointing Authority, which in certain respects at least conform to ordinary court-martial standards, the regulations governing the commissions at issue make several noteworthy departures. At a general court-martial—the only type authorized to impose penalties of more than one year's incarceration or to adjudicate offenses against the law of war, R. C. M. 201 (f) ; 10 U.S.C. §§818–820 (2000 ed. and Supp. III) —the presiding officer who rules on legal issues must be a military judge. ”

“ Procedures for military courts must conform to district-court rules insofar as the President "considers practicable"; (2) the procedures may not be contrary to or inconsistent with the provisions of the UCMJ; and (3) "insofar as practicable" all rules and regulations under §836 must be uniform, a requirement, as the Court points out, that indicates the rules must be the same for military commissions as for courts-martial unless such uniformity is impracticable, ante, at 620, 622, and n. ”

“ United States, 517 U.S. 748, 756–758, 760 (1996) . Concentration of power puts personal liberty in peril of arbitrary action by officials, an incursion the Constitution's three-part system is designed to avoid. ”

“ See ante, at 632–633; 1 Int'l Comm. of Red Cross, 1 Customary Int'l Humanitarian Law 355 (2005) (explaining that courts are "regularly constituted" under Common Article 3 if they are "established and organised in accordance with the laws and procedures already in force in a country") .
[p. 644] The regular military courts in our system are the courts­martial established by congressional statutes. Acts of Congress confer on those courts the jurisdiction to try "any person" subject to war crimes prosecution. ”

“ And any suggestion of executive power to interfere with an ongoing judicial process raises concerns about the proceedings' fairness. Again, however, courts­martial provide the relevant benchmark. Subject to constitutional limitations, see Ex parte Milligan, 4 Wall. 2 (1866) , Congress has the power and responsibility to determine the necessity for military courts, and to provide the jurisdiction and procedures applicable to them. ”