A federal appeals court on Monday overturned an unprecedented ruling by a lower-court judge that permitted a criminal defense attorney to see classified evidence under the Foreign Intelligence Surveillance Act, a major domestic spying law.

The January ruling by U.S. District Judge Sharon J. Coleman in Chicago would have allowed the attorneys for a terrorism defendant to see the top-secret material the government had submitted to obtain a warrant under FISA — something no court had ever allowed before.

The defendant, Adel Daoud, is accused of plotting to bomb a downtown Chicago bar in 2012.

“The adversarial system is integral to safeguarding the rights of all citizens,” Coleman wrote in January. “This court believes that the probable value of disclosure and the risk of nondisclosure outweigh the potential danger” of allowing the attorney, with proper security clearances, to see the material.

But in a strongly worded opinion, a three-judge panel of the U.S. Court of Appeals for the 7th Circuit said Coleman “disobeyed the statute” by ordering the disclosure of the materials without first determining whether the surveillance was lawfully authorized.

“Although she . . . concluded that she was ‘capable of making such a determination’ . . . she refused to make the determination,” wrote Judge Richard Posner for the panel. Posner, a noted conservative jurist, was appointed to the appeals court by President Ronald Reagan.

FISA is “an attempt to strike a balance between the interest in full openness of legal proceedings and the interest in national security, which requires a degree of secrecy concerning the government’s efforts to protect the nation,” he wrote.

“Terrorism is not a chimera,” Posner wrote. “With luck, Daoud might have achieved his goal of indiscriminately killing hundreds of Americans.”

In a concurring opinion, Judge Ilana Rovner highlighted the defendant’s bind. Daoud sought relief based on a Supreme Court ruling in Franks v. Delaware, which held that a warrant could be invalidated if it was premised on misrepresentations or omissions. But the secrecy shrouding the FISA process “renders it impossible for a defendant to meaningfully obtain relief” under Franks, she wrote.

“I believe it is time to recognize that Franks cannot operate in the FISA context as it does in the ordinary criminal context,” where the defense ordinarily has access to the warrant application.

Daoud’s attorneys criticized the ruling. “Philosophically, I could not disagree more with Judge Posner and the court,” said attorney Thomas Durkin. “The adversarial process is far greater than the balancing of society’s interest in openness. It is the foundation of civil liberties in this country. This is but another step in the continued creation of a two-tiered system of justice in federal courts.”

Patrick Toomey, a staff attorney with the American Civil Liberties Union, said, “The fairness of the criminal process is undermined when a defendant and his lawyers are barred from accessing materials that go to the heart of the government’s investigation — especially given what we know today about the breadth and complexity of the government’s surveillance methods.”