The Supreme Court today ruled against a California man who had been escorted off Vandenberg Air Force Base in California after protesting in a designated area outside the main gate of the base.

For years John Apel, an antiwar activist, demonstrated in a protest zone adjacent to public Highway 1. But after he was convicted of trespass for going beyond the designated protest area in 2003 and 2007 , he was barred by authorities from returning to the protest site. When he attempted to return in 2010 he was convicted of violating a federal law that makes it a crime to reenter a federal military installation if an individual has been barred from the base.

Apel appealed his conviction arguing in part that the law did not apply to him because although the federal government owned the land where the protest occurred, it allowed state and local governments to use it as a public highway. He said the law should apply only where the military exercises exclusive possession and control of the land, and not on land that was open to the public and even designated as a protest zone. A federal appeals court ruled in Apel's favor.

Today a unanimous Supreme Court threw out the appeals court ruling. The Justices held the law does not require the military to have exclusive use of the land.

"The fact that the Air Force chooses to secure a portion of the Base more closely - be it with a fence, a checkpoint, or a painted green line - does not alter the boundaries of the Base or diminish the jurisdiction of the military commander," wrote chief Justice John Roberts.

Roberts said, "We decline Apel's invitation to require civilian judges to examine U.S. military sites around the world, parcel by parcel, to determine which have roads, which have fences, and which have a sufficiently important, persistent military purpose. The use-it-or lose-it rule that Apel proposes would frustrate the administration of military facilities and raise difficult questions for judges, who are not expert in military operations."

Roberts noted that many U.S. Military sites around the world, including the Washington Navy yard and the United States Air Force Academy have roads running through them that are freely used by the public.

Although Apel had also argued that his First Amendment rights had been violated, the Supreme Court declined to rule on that constitutional question today because it had not been reached by the appeals court.