Eric R. Haren*
In Hamdan, the Court made clear that the Judiciary will not accept wartime assertions of exigency or emergency without evidence, and ensured that the courts will remain engaged in inter-branch debate on matters of national security. This was envisioned by the Framers and reiterated in Justice Jackson’s famous concurrence in Youngstown.
The Supreme Court’s decision last term in Hamdan v. Rumsfeld1 represents a powerful shift toward congressional responsibility, and away from executive prerogative, in America’s struggle against Al-Qaeda. Fifty-four years had passed since the Supreme Court of the United States last repudiated a significant executive measure taken to protect national security during ongoing hostilities. In that case, Youngstown Sheet and Tube v. Sawyer, the Court struck down President Truman’s seizure of the steel mills during the Korean Conflict.2 In his concurring opinion in Youngstown, Justice Robert Jackson devised a three-category analytical framework that became the controlling law in this area.3 While the majority in Hamdan did not rely on Jackson’s analysis4 in striking down the President’s military commission regime, its opinion adds substance to Jackson’s three-category framework in a manner that restricts executive authority and demands clearer action from Congress. Additionally, the Court in Hamdan firmly cemented the Judiciary’s role in answering wartime separation of powers questions. The net result requires Congress to legislate, rather than delegate, on wartime matters, and ensures the continued existence of a judicial check on governmental action. Hamdan strengthens the separation of powers doctrine that underlies our national government.
I. Justice Jackson’s Three-Category Framework
Our constitutional system was designed to foster inter-branch debate. However, after September 11th, 2001, that system came under strain, principally from ambitious assertions of sole executive power. The President sought, on his own exclusive authority, to conduct extensive electronic surveillance; to detain for years, without trial, American citizens on American soil; and to try alien enemy combatants by military tribunal, with the potential penalty of death. The merits of those policies aside, presidential arrogations of those powers, without clear authorization from Congress, constituted an extraordinary challenge to the separation of powers doctrine, the “essential precaution in favor of liberty.”5
Hamdan represents a judicial circumscription of those ambitious executive assertions in three critical ways, all derived from the legal test that long has governed wartime separation of powers law. That test comes from Justice Jackson’s concurring opinion in Youngstown, which articulated a three-category analytical framework for evaluating the legality of executive action.6 In the first category:
When the President acts pursuant to an express or implied authorization of Congress, his authority is at its maximum, for it includes all that he possesses in his own right plus all that Congress can delegate. In these circumstances, and in these only, may he be said (for what it may be worth), to personify the federal sovereignty. If his act is held unconstitutional under these circumstances, it usually means that the Federal Government as an undivided whole lacks power.7
In the second category:
When the President acts in absence of either a congressional grant or denial of authority, he can only rely upon his own independent powers, but there is a zone of twilight in which he and Congress may have concurrent authority, or in which its distribution is uncertain. Therefore, congressional inertia, indifference or quiescence may sometimes, at least as a practical matter, enable, if not invite, measures on independent presidential responsibility. In this area, any actual test of power is likely to depend on the imperatives of events and contemporary imponderables rather than on abstract theories of law.8
In the third category:
When the President takes measures incompatible with the expressed or implied will of Congress, his power is at its lowest ebb, for then he can rely only upon his own constitutional powers minus any constitutional powers of Congress over the matter. Courts can sustain exclusive Presidential control in such a case only be disabling the Congress from acting upon the subject. Presidential claim to a power at once so conclusive and preclusive must be scrutinized with caution, for what is at stake is the equilibrium established by our constitutional system.9
This framework has served as an important mode of analysis for determining the legality of executive action in the national security arena.10 Jackson’s analysis turns on whether Congress, in the proper exercise of its own constitutional power, has expressly or impliedly approved or prohibited presidential action. The institutional focus on Congress is the proper mode of analysis, even on national security questions, for two reasons. First, although both elected branches possess power related to military force and foreign affairs, only Congress possesses Article I powers to declare war, to provide for the armed forces, to make rules and regulations for the land and naval forces, and to define and punish offenses against the law of nations. Second, only Congress possesses the sweeping grant of implied power contained within the Necessary and Proper Clause.11 That clause grants power to Congress to pass laws that are “Necessary and Proper” not only to the execution of congressional power, but also to powers vested in the other branches.12 And, because the President must faithfully execute the laws of the United States under Article II, he cannot contravene the word of Congress expressed in law unless the authority in question is exclusively assigned to the President.13 As a result, as Justice Kennedy recognized in his Hamdan concurrence, Jackson’s focus on congressional action is the proper way to assess the legality of executive action, even in wartime.14
Although the majority in Hamdan did not focus on Jackson’s three categories, the Court reaffirmed a key principle of Youngstown: that the President may not disregard congressional limitations on presidential action when Congress properly acts pursuant to its own power.15 TheHamdan majority made two relevant determinations in that regard. First, it held that neither Congress’s Authorization for the Use of Military Force16 (“AUMF”) after September 11th nor its passage of the Detainee Treatment Act of 200517 (“DTA”) constituted sufficiently clear authorization for the President’s military commission regime.18 Second, it held that the military commission regime violated the Uniform Code of Military Justice (“UCMJ”) by (1) contravening the statutory principle that commission procedures should be as uniform as practicable for court-martial proceedings and (2) by violating the Geneva Conventions’ Common Article 3 requirement (incorporated by reference into the UCMJ) of a “regularly constituted court.”19
Those holdings make clear that Congress must clearly authorize extraordinary exercises of war powers and that the President must follow every legislative restriction properly enacted by Congress. Thus, by any measure, Hamdan is a watershed separation-of-powers decision. However, much of Hamdan‘s language is specific to the tensions among the President’s military commission regime, the UCMJ, the Geneva Conventions, and the law of war. As a result, in future cases presenting different questions, courts likely will reach in the first instance for more abstract modes of analysis. As Justice Kennedy noted in his Hamdan concurrence, the “proper framework for assessing whether Executive actions are authorized is the three-part scheme used by Justice Jackson.”20 As a consequence, it is a worthwhile exercise to ask how that framework interacts with the Hamdan decision.
II. Hamdan‘s Impact on Justice Jackson’s Categories
Although the Hamdan Court did not expressly base its analysis on Justice Jackson’s framework, the Court’s reasoning – basing the legality of the President’s actions on whether he contravened congressional enactments – is precisely the course of reasoning mandated by Jackson’s framework. From that perspective, the Hamdan decision adds substance to each of Jackson’s categories.
First, by imposing a clear-statement requirement on Congress, at least in areas as restrictive of liberty as military commissions, Hamdan limits the degree to which the Executive successfully can argue that an action is in the first category.21 The Hamdan Court considered both the AUMF and the DTA and could have determined that either statute constituted congressional authorization for the President’s military commission regime. Indeed, the AUMF had already been interpreted in an earlier case to have authorized detention of enemy combatants as a fundamental incident of waging war.22 In addition, the DTA was specifically passed to limit jurisdiction over habeas corpus petitions by Guantanamo detainees.23 Either statute could have served a congressional authorization for military commissions had the Court been inclined in that direction.24 However, the Court took a different course, requiring Congress to speak more clearly before authorizing a presidential regime that raised “separation-of-powers concerns of the highest order.”25 Such a clear-statement requirement should hinder future presidential efforts to draw expansive power from nebulous congressional enactments. Wartime presidents thus will be forced to involve Congress more often and more extensively, a result that reinforces a system that creates policy through “a deliberative and reflective process engaging both of the political branches.”26
Second, Hamdan makes clear that courts should not simply defer to presidential claims of military exigency, adding considerable substance to Justice Jackson’s second category.27 The question in this category is whether, in the absence of a congressional voice, the courts should take as preclusive the President’s word that a certain measure is imperative. In Hamdan, the President cited the “danger posed by international terrorism” as a justification for departing from standard court-martial procedures.28 Hamdan had been detained for several years without charge and was not charged by military commission until after he filed suit seeking his release. Without any substantial evidence that military exigency necessitated a departure from court-martial proceedings in Hamdan’s case, the Court refused to defer to the President’s assertion. That refusal adds substance to Jackson’s second category because it implies courts actually should inquire into the “imperatives of events” rather than granting total deference to executive assertions. Thus, post-Hamdan, when Congress is silent, at least the courts can serve as a counterweight to expansive assertions of executive power.
Third, Hamdan narrows the range of exclusive executive powers, which are the only presidential actions than can survive Jackson’s third category. With respect to this category, the President generally argues that his exclusive Article II powers are broad enough to withstand judicial scrutiny, even if Congress has prohibited a particular executive action. In support of that claim, the Executive often suggests that the courts should construe broadly the clauses vesting the “executive Power”29 and the “Commander in Chief”30 power in the President. That argument’s theoretical underpinnings rest on a historical understanding of the meaning of “executive Power” when the Constitution was ratified. On this view, “executive Power” meant those powers possessed by the British Crown. Thus, the argument goes, the President’s “executive Power[s]” under Article II must include every royal executive power except those expressly taken away and granted to Congress by Article I.31 In Hamdan, President Bush argued that Article II provided exclusive authority for instituting military commissions,32 meaning that the military commissions were legal even if Congress had clearly barred their use. Had a claim to sole executive power found favor with a majority of the Court, the President’s military commission regime necessarily would have been upheld.33 The Court said as much two years earlier in Hamdi v. Rumsfeld, when it wrote, concerning detention authority, “We do not reach the question whether Article II provides such [exclusive] authority, however, because we agree with the Government’s alternative position, that Congress has in fact authorized Hamdi’s detention, through the AUMF.”34 And yet, even though the HamdanCourt found that Congress had barred the Executives action, the majority again struck down the President’s actions without addressing the Executive’s claim to exclusive authority. Thus, by necessary implication, the Court clearly was unwilling to validate any claim to exclusive Article II authority,35 which, as noted above, is the only type that can survive analysis under category three of Jackson’s framework. Based on the Court’s clear unwillingness even to consider the Executive’s sole authority argument in Hamdan, the range of actions that can withstand category-three analysis is probably quite narrow. As a result of the foregoing,Hamdan fleshes out Justice Jackson’s three-category framework and helps explain much of the substantive law that will apply in future cases.
III. Hamdan‘s Impact on Future Judicial Review of Military Commission Determinations
For Hamdan‘s substantive impact to have significance, however, courts must be able to hear new cases and render decisions. In that regard, Hamdan is also significant because it makes clear that courts can continue to review military commission proceedings broadly, at least after the commissions make their determinations. First, the Hamdan majority engaged in a rather strained analysis to establish that the DTA did not deprive the Court of jurisdiction to hear cases pending on the date of the DTA’s enactment. That result suggests that the Court will accept nearly any plausible argument to sustain its own jurisdiction in cases where curtailing jurisdiction would raise serious constitutional questions.36
Second, in the military commission context, Hamdan establishes that recent congressional enactments provide for broad, substantive judicial review of commission determinations. Justices Scalia, Thomas, and Alito, seeking to stave off jurisdiction over Hamdan’s particular case, indicated that judicial review of military commission determinations would be quite searching. In particular, those justices argued that the DTA granted jurisdiction to the Court of Appeals for the D.C. Circuit to review every aspect of the military commissions for consistency with the Constitution and laws of the United States.37 The Military Commissions Act of 200638 (“MCA”), recently passed by Congress in reaction to Hamdan, authorizes judicial review in the D.C. Circuit and in the Supreme Court with language nearly identical to that in the DTA.39 The justices in the Hamdan majority certainly are unlikely to take a more restrictive view of that language than did the dissenters. Thus, extrapolating from the dissenting justices’ interpretations of the DTA in Hamdan, the judiciary can continue post-conviction review ofevery aspect of military commission proceedings to examine their consistency with the Constitution and laws of the United States. That result ensures judicial participation in the inter-branch debate that sustains our system of separated powers.
Hamdan will encourage accountability both between branches and between our government and its people. It requires the Executive to seek authorization from Congress more frequently, increasing executive accountability both to the legislature and to the people. Additionally it requires that, when Congress acts, it must act with greater clarity and specificity, thus making legislators more accountable to their constituents. Hamdan also makes clear that the judiciary will not accept wartime assertions of exigency or emergency without evidence, and ensures that the courts will remain engaged in the inter-branch debate. Legislators and executive officials should, as a result, be expected to make more reasoned judgments and provide more substantial evidence for their decisions.
To be sure, we face a dangerous enemy who often hides, blends in with civilian populations, and wears no uniforms. Nevertheless, the drafters of our Constitution did not create an all-powerful Executive with the exclusive authority to deal with every national security problem. Madison thought our government’s structure of separated powers was the most effective safeguard of our liberties. In Hamdan, the Supreme Court vindicated that principle in two critical ways. First, the Court gave substance to all three of Justice Jackson’s analytical categories in a manner that restricts executive authority and demands clear congressional participation. Second, the decision makes clear that the judiciary remains committed to ensuring that governmental action remains within statutory and constitutional boundaries, both generally and specifically to the military commission context. Congress has responded to Hamdan by passing extensive legislation, which the President undoubtedly will enforce. The judiciary will then apply the reasoning developed in Hamdan as it works its way through individual cases. Such inter-branch tension was the vision of our founding generation. Because of the Hamdandecision, that vision is no longer in immediate jeopardy.
* Eric R. Haren is a Law Clerk to Chief Judge Danny J. Boggs, United States Court of Appeals for the Sixth Circuit.
 126 S. Ct. 2749 (2006).
 343 U.S. 579 (1952).
 Id. at 634-643 (Jackson, J., concurring).
 In his concurrence, Justice Kennedy did base his analysis on Jackson’s Youngstown categories. Hamdan, 126 S. Ct. at 2799-800 (Kennedy, J., concurring).
 THE FEDERALIST NO. 47 (James Madison) (Clinton Rossiter ed., 1961).
 Jackson, a former Attorney General under President Franklin Roosevelt, formerly was a strong advocate of executive power. See generally Acquisition of Naval and Air Bases in Exchange for Over-Age Destroyers, 39 Op. Att’y Gen. 484 (1940) (arguing that the president had unilateral authority under the law to dispose of naval vessels in exchange for the acquisition of rights from the British government to establish military bases abroad). Nevertheless, the three-category test Jackson penned as a justice focuses on congressional authorization, rather than executive prerogative, in assessing the legality of executive action.
 Youngstown, 343 U.S. at 636-37.
 Id. at 637.
 Id. at 637-38.
 See Dames & Moore v. Regan, 453 U.S. 654, 668 (1981); Hamdi v. Rumsfeld, 542 U.S. 507, 562-63 (2004) (Scalia and Stevens, JJ., concurring); id. at 583 (Thomas, J., dissenting).See also Neal K. Katyal & Laurence H. Tribe, Waging War, Deciding Guilt: Trying the Military Tribunals, 111 YALE L.J. 1259, 1274 (2002); Curtis A. Bradley & Jack L. Goldsmith, The Constitutional Validity of Military Commissions, 5 GREEN BAG 249, 253 (2003).
 See generally McCulloch v. Maryland, 17 U.S. (4 Wheat.) 316 (1819).
 See U.S. CONST. art. I, § 8, cl. 18 (“To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof“) (emphasis added).
 Youngstown, 343 U.S. at 637-38 (“Courts can sustain exclusive Presidential control in such a case only be disabling the Congress from acting upon the subject.”).
 126 S. Ct. at 2800 (Kennedy, J., concurring).
 Justice Stevens, writing for a four-justice plurality in Part V of Hamdan, cited Justice Jackson’s Youngstown concurrence. Id. at 2774 n.23 (citing Youngstown, 343 U.S. at 637 (Jackson, J., concurring)). Justice Kennedy, concurring with Justice Stevens’s majority opinion except as to Parts V and VI.d.iii, relied more heavily on Jackson’s Youngstown concurrence.Id. at 2800 (citing Youngstown, 343 U.S. at 635-37 (Jackson, J., concurring)).
 Pub. L. No. 107-40, 115 Stat. 224 (2001).
 Pub. L. No. 109-148, §§ 1001-1006, 119 Stat. 2739, 2739-44 (to be codified at 42 U.S.C. 2000dd to 2000dd-1) [hereinafter DTA].
 Hamdan, 126 S. Ct. at 2776.
 See id. at 2789-98.
 Id. at 2800 (Kennedy, J., concurring).
 See supra text accompanying note 7.
 See Hamdi, 542 U.S. at 518 (“We conclude that detention of individuals falling into the limited category we are considering, for the duration of the particular conflict in which they were captured, is so fundamental and accepted an incident to war as to be an exercise of the ‘necessary and appropriate force’ Congress has authorized the President to use.”).
 See DTA § 1005(e).
 Cf. Hamdi at 519-20.
 See Hamdan, 126 S. Ct. at 2800 (Kennedy, J., concurring) (citing Loving v. United States, 517 U.S. 748, 756-58, 760 (1996)).
 Id. at 2799 (Kennedy, J., concurring).
 See supra text accompanying note 8.
 126 S. Ct. at 2792.
 U.S. CONST. art. II, § 1, cl. 1.
 Id. at art. II, § 2, cl. 1.
 See, e.g., John C. Yoo, The Continuation of Politics By Other Means: The Original Understanding of War Powers, 84 CAL. L. REV. 167, 197, 270 (1996) (“In adopting a new Constitution, the Framers consciously acted in the context of the British Constitution, under which they had lived as English colonists. . . . The Philadelphia Convention intended to modify, rather than transform, the political relationship between the executive and legislative branches in the realm of war powers . . . .”). See also Alexander Hamilton (Pacificus), Pacificus-Helvidius Debate, GAZETTE U.S., June 29, 1793 (“The general doctrine of our Constitution . . . is that the executive power of the nation is vested in the President; subject only to the exceptions and qualifications, which are expressed in the instrument.”) (emphasis added),available at http://teachingamericanhistory.org/library/ index.asp?document=429.
 See Brief for the Respondent at 21, Hamdan, 126 S. Ct. 2749 (No. 05-184) (“The President’s war power under Article II, Section 2, of the Constitution includes the inherent authority to create military commissions even in the absence of any statutory authorization, because that authority is a necessary and longstanding component of his war powers.”).
 See Youngstown, 343 U.S. at 637-38 (“When the President takes measures incompatible with the expressed or implied will of Congress, his power is at its lowest ebb, for then he can rely only upon his own constitutional powers minus any constitutional powers of Congress over the matter. Courts can sustain exclusive Presidential control in such a case only be disabling the Congress from acting upon the subject.”).
 542 U.S. at 517.
 Indeed, only Justice Thomas’s dissent came close to addressing a claim of independent and exclusive presidential power to institute military commissions under Article II. See Hamdan, 126 S. Ct. at 2849 (Thomas, J., dissenting) (“The President’s findings about the nature of the present conflict with respect to members of al Qaeda operating in Afghanistan represents a core exercise of his commander-in-chief authority that this Court is bound to respect.”).
 Cf. generally INS. v. St. Cyr, 533 U.S. 289, 305 (2001) (applying a clear-statement rule to avoid the conclusion that Congress had suspended the writ of habeas corpus).
 Hamdan, 126 S. Ct. at 2818-19 (Scalia, J., joined by Thomas and Alito, JJ., dissenting) (The DTA “grants the D.C. Circuit authority to review, ‘to the extent the Constitution and laws of the United States are applicable, whether the use of such standards and procedures to reach the final decision is consistent with the Constitution and laws of the United States’. . . . [T]he ‘standards and procedures specified in’ Order No. 1 include every aspect of the military commissions, including the fact of their existence and every respect in which they differ from courts-martial. . . . The D.C. Circuit thus retains jurisdiction to consider these claims on post-decision review, and the Government does not dispute that the DTA leaves unaffected our certiorari jurisdiction under 28 U.S.C. § 1254(1) to review the D.C. Circuit’s decisions.”).
 Pub. L. No. 109-366, 120 Stat 2600 (2006) (codified in scattered sections of 10 and 18 U.S.C.) [hereinafter “MCA”].
 Compare DTA § 1005(e)(2)(C) (“The jurisdiction of the United States Court of Appeals for the District of Columbia Circuit on any claims with respect to an alien under this paragraph shall be limited to the consideration of . . . to the extent the Constitution and laws of the United States are applicable, whether the use of such standards and procedures to make the determination is consistent with the Constitution and laws of the United States.”) with MCA 3(a)(1) (refer specifically to amended § 950(g)(c)) (“The jurisdiction of the Court of Appeals on an appeal under subsection (a) shall be limited to the consideration of (1) whether the final decision was consistent with the standards and procedures specified in this chapter; and (2) to the extent applicable, the Constitution and the laws of the United States.”).