A federal appeals court has scheduled oral arguments for later this year on a soldier's lawsuit that claims the war against Islamic State is illegal.

The lawsuit seeks to blaze a path for judicial review of presidential war-making where many previous efforts have failed, and the granting of oral arguments was not guaranteed.

Courts historically have been reluctant to rule on the legality of military campaigns, but attorneys for Army Capt. Nathan Michael Smith believe that as a member of the military he can establish standing, a major hurdle, and the facts are on his side.

"A decision in Smith's favor would re-establish that war power cases are appropriate issues for the courts," said Louis Fisher, a Constitution Project scholar and former senior specialist in separation of powers at the Library of Congress.

Fisher said the granting this week of oral arguments for Oct. 27 was an "interesting development," and said "the issues were not well handled by the district court," which dismissed Smith's case last year.

"Frankly, I am not surprised," said Yale Law School professor Bruce Ackerman, who represents Smith alongside attorney David Remes.

"Our briefs argued that the district court failed to cite, let alone discuss, key Supreme Court precedents, and that oral argument was necessary to fully assess the fundamental constitutional and statutory issues raised by this case," he said.

Smith, then a Kuwait-based intelligence analyst, filed his lawsuit last year against President Barack Obama, saying he supported the war effort but his conscience bothered him.

U.S. District Judge Colleen Kollar-Kotelly ruled in November Smith lacked standing, that his claims dealt with a matter traditionally handled by the political branches of government and that Congress had implied approval by providing funding.

The Obama administration argued that, in addition to implicit approval through spending bills, Congress granted legal authority through unrepealed 2001 and 2002 war authorizations passed after 9/11 and to topple Saddam Hussein, a claim disputed among scholars.

In its first substantial filing in the case, the Trump administration argued in June that Smith's case was weakened by his recent departure from active-duty service. Smith's attorneys say he remains a "ready reservist" until May 2018.

Ackerman and Remes argue the 1973 War Powers Resolution clearly is being violated, as the military campaign in Iraq and Syria has lasted about three years without specific congressional authorization.

The Constitution grants Congress the power to declare war and the War Powers Resolution limits use of force abroad to 60 days without congressional authorization, with an extra 30 days allowed for disengagement.

Some lawmakers have called for passage of a war authorization specifically against the Islamic State group, but specific draft proposals have gone nowhere.

George Washington University law professor Jonathan Turley, who represented 10 congressmen in an unsuccessful lawsuit against Obama's military campaign in Libya, says the case "puts in sharp relief the courts constantly moving the goalposts for standing."

"The courts have created an absolute mess with standing doctrine — they have effectively created a presidential immunity from court review that the framers never intended," Turley said. "Many of us have been waiting for courts to address this anomaly that they have created."