AUMFs also have legal significance. They buttress the president’s powers and, consistent with Supreme Court precedent, provide legal support when such aspects of war-fighting as electronic surveillance, detention of enemy combatants and use of deadly force against American nationals who have joined the enemy are challenged in court.

One can argue whether Congress’s constitutional power to declare war serves principally to distinguish formally among enemies, friends and neutrals, or has broader effect. However, AUMFs have become particularly important in the aftermath of the 9/11 terror attacks, as federal courts have involved themselves to an unprecedented degree in scrutinizing such activities. The relevant judicial decisions often cite the existence of an AUMF.

Despite the benefits of traditional AUMFs, President Obama’s proposal is fundamentally flawed. Attempting to obtain political cover for his strategy to fight Islamic State, also known as ISIS or ISIL, he has asked Congress to ban “enduring offensive ground operations” and to terminate the authorization after three years.

Congress cannot restrain the president’s core constitutional authority to wage war, even when congressionally imposed restrictions are minor—as was true with 2001 legislation that purported to limit the president’s authority to place U.S. armed forces under the command of foreign officers as part of U.N. peacekeeping missions. Congress did not bar the president from placing U.S. troops under foreign command, but merely required that certain procedures be followed in such cases. Even so, the Justice Department’s Office of Legal Counsel correctly concluded that “it is unconstitutional for Congress to place conditions, whether substantive or procedural, on the president’s exercise of his constitutional authority as Commander-in-Chief.”

Every president from Richard Nixon on has maintained that the 1973 War Powers Resolution, requiring that the president notify Congress within 60 days of committing U.S. troops abroad, is unconstitutional. Yet each president also has—voluntarily—complied with it. Except President Obama, who directed U.S. military intervention in Libya and claimed that the 1973 law did not apply because the effort was too limited to be called a “war.” Yet now the Obama AUMF purports to impose major constraints on the president’s commander-in-chief authority—both his own, and his successors’.

The Founders were careful to vest responsibility for waging war in a unitary executive, rather than in a multimember legislature. They made the decision based on their historical knowledge that the unity of command is the prerequisite for military success, and on their own experience during the Revolutionary War—which had been managed by committees of the Continental Congress. James Wilson, among the most learned lawyers of the Founding generation, reasoned that, with a unitary executive “[w]e secure vigor. We well know what numerous executives are. We know there is neither vigor, decision nor responsibility in them.”

The Founders also trusted in the power of political accountability, which is why they decisively rejected an executive branch composed of a president and executive council in favor of the unitary executive branch we now enjoy. In Federalist No. 70, Alexander Hamilton observed that political accountability can exist only if the president cannot shift responsibility for his actions onto others: “It often becomes impossible, amid mutual accusations, to determine on whom the blame of punishment of pernicious measures, ought really to fall.” The public, he concluded, would be “left in suspense about the real author” of bad policy.

If Congress were to limit President Obama’s commander-in-chief power by banning what his resolution calls “enduring offensive combat operations”—whatever that means—Congress would effectively operate as an executive council to Mr. Obama, allowing him to evade accountability for his halfhearted prosecution of war against ISIS. It is bad enough that legislation to tie a president’s hands is being proposed by a president. That it is proposed by this president, who has been so willing to exceed his constitutional authority in domestic affairs—by rewriting immigration laws, anti-narcotics laws, ObamaCare and so on—underscores the administration’s cynicism and its disdain for the Constitution.

If Congress buys into this presidential plan it will set a dangerous precedent that might do lasting damage to the separation of powers. With the two political branches seemingly in accord on joint responsibility for waging war, the federal courts might bless this arrangement, handicapping future presidents.

In recent years, congressional Democrats have been content to accommodate President Obama, whether he chose to enlarge the president’s constitutional prerogatives or diminish them. Congressional Republicans, having chosen to litigate against President Obama when he invaded Congress’s lawmaking authority by rewriting ObamaCare, should display the same principled determination to uphold the president’s constitutional prerogatives. No AUMF is better than one that is constitutionally flawed.

Mr. Mukasey served as U.S. attorney general (2007-09) and as a U.S. district judge for the Southern District of New York (1988-2006). Mr. Rivkin is a constitutional litigator and served in the Justice Department and White House Counsel’s Office in the Reagan and George H.W. Bush administrations.

Source: http://www.wsj.com/articles/michael-b-mukasey-and-david-b-rivkin-jr-another-obama-collision-with-the-constitution-1424391724