Among the most extraordinary powers claimed by both President Bush and President Obama as part of the post-9/11 “war on terrorism” is the power to nullify — or ignore — jury verdicts of acquittal in federal criminal cases involving terrorism.

Ever since the founding of the United States, it has been a fundamental principle of American criminal jurisprudence that the executive branch has the power to charge and prosecute people for criminal offenses while the judicial branch has the power to determine whether they’re guilty or not.

Another fundamental principle, one expressly guaranteed by the Bill of Rights, is that in all criminal prosecutions, the accused has the right to have a jury of his peers, rather than the judge, weigh the evidence and determine whether the prosecution has proven his guilt beyond a reasonable doubt.

Historically, jury verdicts in criminal cases have always been considered final. When a jury comes back into the courtroom with a “Not Guilty” verdict, the federal judge immediately releases him from custody, even if everyone else, including the judge, thinks the jury has made a mistake.

These principles of criminal jurisprudence have been a hallmark of American law since the founding of the Republic.

They came to a screeching halt on 9/11, when President Bush, the Justice Department, and the Pentagon announced that they now possessed the power to treat suspected terrorists either as criminal defendants or as enemy combatants, at their option.

As part of that announcement, the president and the military quietly assumed the power to nullify — that is, ignore — federal-court jury verdicts of acquittal in terrorism cases and treat the acquitted person as an enemy combatant, including subjecting him to indefinite incarceration.

The obvious question arises: What’s the point of sending a suspected terrorist down the criminal-defendant road in the first place? If they’re going to ignore a jury’s verdict of acquittal anyway, why not simply treat him as an enemy combatant and not waste all the time and money involved in a federal criminal prosecution?

In fact, two legal scholars — Benjamin Wittes and Jack L. Goldsmith — recently made that point in an op-ed entitled “The Best Trial Option for KSM: Nothing” in the Washington Post. They reached the logical conclusion: Since the U.S. military is going to take a person acquitted of terrorism by a federal court jury into custody as an enemy combatant, what’s the point of having a federal court trial in the first place?

The answer is that a federal-court proceeding provides an aura of legitimacy and respectability, but without any risk to the government.

If a person is convicted of terrorism in federal court, then U.S. officials can say that he’s been accorded due process of law before he’s sentenced to a long prison term.

If the person is somehow acquitted, however, no sweat. The minute the jury announces its verdict, a contingent of U.S. soldiers swoops into the courtroom, grabs the acquitted defendant, and whisks him off to some military incarceration camp, possibly for the rest of his life.

Where did President Bush and the Pentagon come up with the idea of this novel and extraordinary power, one that President Obama has eagerly embraced? It’s impossible to say for certain, but one good possibility is Nazi Germany. As part of the Nazi legal system, whenever German prosecutors failed to secure a criminal conviction, the Gestapo would simply take the person into custody and railroad him into a concentration camp.

In fact, German judges got in the habit of contacting the Gestapo before they released an acquitted defendant to see if the Gestapo wanted him. I can’t help but wonder whether U.S. federal judges will be doing the same thing with the Pentagon whenever a jury returns to the courtroom with a verdict of acquittal in terrorism prosecutions.

Jacob Hornberger is founder and president of The Future of Freedom Foundation.