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.

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?