Washington Post Tehran correspondent Jason Rezaian was arrested one year ago on July 22, 2014. He is currently on trial in Iran for espionage charges. The U.S. government, The Post, the Committee to Protect Journalists and his family all say he was simply working as a journalist and that he should be freed immediately. (Whitney Shefte/The Washington Post)

ONE YEAR ago on Wednesday, Iranian Revolutionary Guards broke into and ransacked the Tehran home of Post reporter Jason Rezaian and arrested him and his wife, Yeganeh Salehi. There began a blatant abuse of human rights and Iranian and international law that continues to this day.

As a petition submitted by The Post Tuesday to the United Nations Working Group on Arbitrary Detention summarizes it, “since his arrest, Rezaian has been harshly interrogated for days and weeks at a time, kept for long periods in solitary confinement, deprived of his rights to counsel and to consular visitation, and detained for almost a year without trial.” Ms. Salehi was released on bail but remains subject to charges.

Since it finally began on May 26, Mr. Rezaian’s trial has been held in secret before a judge who previously was blacklisted by the European Union for his abuses. According to The Post’s petition, in the three court sessions held at irregular intervals so far, “there have been no live witnesses, no real evidence, and nothing to justify the charges, much less anything to prove that Rezaian is guilty of a crime.”

Though Iran has never publicly disclosed the charges against Mr. Rezaian, his lawyer has said they include espionage and collaborating with hostile governments. Public reports indicate that the only purported evidence authorities presented are an online job application Mr. Rezaian submitted to the Obama administration’s transition team in 2008 and a message to a U.S. consulate about a visa for his wife. No wonder the State Department, which commonly refuses to comment on espionage cases, has called the charges against Mr. Rezaian “patently absurd.”

Mr. Rezaian, 39, has now been detained in Iran longer than any other Western journalist. Born and raised in California, he moved to the country in 2008 with the ambition of promoting greater understanding between Iran and the United States. His reward was to be abruptly and unjustly confined to Tehran’s notorious Evin prison, where his physical and psychological health have undergone a steep decline. Hard-liners in the Iranian regime appear to be using him as a pawn to prevent the very improvement in relations that Mr. Rezaian hoped for.

The Post’s petition spells out the multiple ways that Mr. Rezaian’s detention has violated Iran’s own laws, as well as international conventions. His prolonged solitary confinement was illegal: Though Iranian law limits such treatment to 20 consecutive days, Mr. Rezaian was held in solitary for 90 days or more. Also illegal was the failure to bring formal charges against Mr. Rezaian for more than five months and the severe restriction of his legal representation. Iranian law says no person may be detained for more than a year, unless charged with murder; yet Mr. Rezaian remains imprisoned.

The petition asks for urgent action by the U.N. working group, including an opinion finding Mr. Rezaian’s detention to be a violation of treaties Iran has ratified. We hope the response will be swift. But what’s most needed is action in Tehran. On Wednesday, the country’s deputy foreign minister confirmed that there had been talks with the United States on the case of Mr. Rezaian and other imprisoned Americans for “humanitarian” reasons. Those considerations alone should justify Mr. Rezaian’s immediate release.