What is the most important responsibility of Congress?

Is it protecting the security of the country, the integrity of its political system, and the lives of its military personnel by deciding when and how the U.S. should use military force?

What if the president believed a military conflict was essential for national security? And what if Congress apparently agreed with the president?

And what if Congress still wouldn’t act?

That’s the situation in the United States today. Since August of 2014, American military forces have been conducting operations—airstrikes at first, and then ground operations involving U.S. Special Forces and “advisers”—against the Islamic State.

The action is being taken on the president’s authority and the vague claim that it is authorized by the 2001 Authorization for the Use of Military Force, or AUMF, against those who “planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001”—a date on which ISIL did not exist.

President Obama has repeatedly asked Congress to use its power to declare war to authorize the operation against ISIL. There appears to be no real opposition to the war effort on Capitol Hill. But Congress has not held hearings or a vote of any kind.

The War Powers Resolution of 1973 was passed to govern such a situation. It requires the president to seek congressional approval of military action within 60 days of its commencement. If he does not do so, or if Congress withholds assent, the law says he must withdraw U.S. forces from the conflict.

Arguably, dodging an AUMF vote is a far worse sin against the Constitution than dodging a Supreme Court nomination.

The War Powers Resolution does not require Congress to vote on a presidential request, but it should. Arguably, dodging an AUMF vote is a far worse sin against the Constitution than dodging a Supreme Court nomination. If Congress approved the effort, the law would be satisfied; if Congress voted against it, then the president would either have to withdraw U.S. forces or explain why he thinks he has constitutional authority to act without authorization. But if Congress simply won’t say “yes” or “no,” the military effort exists in a limbo—what the late Justice Robert H. Jackson once called the “zone of twilight in which [the president] and Congress may have concurrent authority, or in which its distribution is uncertain.” Because the division of constitutional power may be unclear, Jackson wrote, “congressional inertia, indifference, or quiescence may sometimes, at least as a practical matter, enable, if not invite, measures on independent presidential responsibility.”

That brings us to the case Smith v. Obama, filed in the D.C. District Court on May 4. The plaintiff in Smith is the U.S. Army captain Nathan Smith. Smith, who is based in Kuwait, has been assigned to “Operation Inherent Resolve,” the American military’s effort to eliminate the Islamic State.

It’s a mission almost everyone in the federal government supports, including Smith. But his orders put him in a difficult place. He believes he is being required to violate his oath to “support and defend the Constitution of the United States.”

Smith’s lawsuit asks the court to “declare that the war against ISIS … violates the War Powers Resolution because the Congress has not declared war or given the president specific statutory authorization to fight the war.” If the court finds in Smith’s favor, the lawsuit argues, and Congress still fails to authorize the war, U.S. military forces will have to disengage from its efforts against ISIS in Iraq and Syria. Further, because Obama has not produced a formal opinion from the Justice Department’s Office of Legal Counsel, Smith argues, the president has violated Article II, which requires that he “take care that the laws be faithfully executed.”

This case seems to meet nearly every definition of a “political question” laid out in the landmark case Baker v. Carr, in which Justice William Brennan for the first time explained why some highly “political” cases can be heard by federal courts and others cannot. A “political question” is not a partisan question; it is a dispute courts simply cannot resolve because it involves deep questions of national policy that have no clear legal answer. According to Baker, a political question involves, among other things,

a textually demonstrable constitutional commitment of the issue to a coordinate political department; . . . or the impossibility of deciding without an initial policy determination of a kind clearly for non judicial discretion; or the impossibility of a court's undertaking independent resolution without expressing lack of the respect due coordinate branches of government; or an unusual need for unquestioning adherence to a political decision already made; or the potentiality of embarrassment from multifarious pronouncements by various departments on one question.

Textual commitment to Congress? Check. Need for policy determination? Check. Danger of lack of respect for other branches? Check. Need to stand by the political decision to deploy troops? Check. Possibility of embarrassment?

Uh, yeah.

Even a federal district judge might hesitate before ordering the president to break off hostilities against a foreign enemy and withdraw forces from the field. It would be an even more daunting leap to issue such an order on the grounds that the president has not consulted (or revealed discussions with) one of his own advisers, whose existence is not even contemplated by the Constitution. If a president believes in good faith that his or her course of action is legal, it’s hard to see how failure to consult a specific subordinate can violate the Constitution.

One lawyer consulting with Smith’s team on the case is Yale’s Bruce Ackerman, a scholar whose summary of the argument for a case like this one in The Atlantic in 2015 led Smith to file his suit. In an email exchange, Ackerman defended this case against the charge that it seeks inter-branch meddling:

The Constitution and the War Powers Resolution commits America to peace—unless the President can organize the support of Congress, and the American People, for war. This raises very different separation of powers issues from those generated in other areas—political checks-and-balances are much more powerful in dealing with federalism issues, as in the Texas case, or the judicial battles over the administration of Obamacare. In contrast, the constitutional commitment to peace can be easily undermined by unilateral presidential war making—as Richard Nixon showed during the closing months of the Vietnam War. In enacting the War Powers Resolution, Congress itself tried to prevent future presidents from undermining the constitutional commitment to peace—and provided judicially administrable rules for the courts to use when serving as the ultimate safeguard of this deeply rooted principle.

The argument against the current state of affairs is a strong one. The argument that there are “rules for the courts to use,” for better or worse, is less so. A court decision stating that the current military operation is unlawful would raise unpredictable legal issues. A court order to the president on his use of military forces, however coyly phrased, would be at best unenforceable. A president who believes his conduct is lawful and the national interest is at stake might very well—and arguably should—refuse to comply with such an order.

What then?

To understand the hazards of this case, imagine for a moment that the plaintiff added a count seeking an order not to Obama but to Congress—requiring the body to debate, and either accept or reject, the president’s request for an AUMF. Ackerman responded, quite correctly, that a U.S. court couldn’t do that:

If we had a system of abstract review, as in Germany or France or elsewhere, there are standard techniques of calling parliament to account if its acts (or failure to act) offend fundamental constitutional principles. But for better and for worse (it's really quite a complicated balance on both sides of the ledger), the American system, since John Marshall, has insisted on concrete cases and controversies. Nobody has standing to urge the Court to declare Congress in default.

It’s not clear to me that Smith’s request for relief is any more “concrete” than court’s theoretical order to Congress would be. Arguably, the only “concrete” resolution would be a court order that Smith himself need not participate in the war effort—the war effort he wants to take part in. The relief Smith and other soldiers are actually seeking—and one they richly deserve—would be a decision by their political leaders to treat the Constitution, the nation’s commitment to military force, and the lives of American personnel as a serious matters, worthy of sustained attention.