Iranian President Mahmoud Ahmadinejad likes to boast about the superiority of Iranian moral values to those of the West.

So, a week before he traveled to the U.N. General Assembly, he sought to divert attention from Iran’s dismal human rights record by intervening to free Sarah Shourd, one of three American hikers who had been jailed for 13 months in Tehran. He claimed this was a gesture of Islamic compassion due to her health problems.

But his gesture rings hollow given that Shourd’s two companions — her fiance, Shane Bauer, and friend Josh Fattal — remain in Evin Prison. Nor can Ahmadinejad’s gesture hide the horrors perpetrated on hundreds of Iranians imprisoned since rigged elections last year.

The three Americans were arrested while hiking in Iraq’s scenic north, near the unmarked border with Iran. Shourd and Bauer were working in Damascus, Syria, and Fattal had joined them for a hiking holiday. Iran claims the three illegally crossed the border, but they may have been seized on the Iraqi side by Iranian border guards.

Until last weekend, no charges had been lodged against the three, and their interrogation stopped months ago. “They have been held as hostages” while the regime sought to get something for their release, said Iran expert Gary Sick.

When Ahmadinejad finally intervened on Shourd’s behalf, his political enemies in the Iranian judiciary at first canceled her release, and then imposed $500,000 “bail” — meaning ransom. Shourd was flown out on a jet belonging to the government of Oman, a country friendly to both the United States and Iran; the Omanis also may have put up the money.

But just before Shourd was freed, Iran charged the three hikers with spying. Let’s hope the Iranians understand that another show trial — of the two men — would be a huge blot on their moral pretensions and their country’s name.

Iran already embarrassed itself a few months ago with a televised show trial of onetime top officials jailed because they supported candidates who ran against Ahmadinejad. The accused, looking haggard, mumbled staged confessions in a spectacle reminiscent of the Stalin era at its worst.

The world has been treated to other recent examples of Iran’s sham “justice,” including the case of Sakineh Mohammadi Ashtiani, an Iranian woman sentenced to death by stoning for adultery. Ahmadinejad may disdain criticism from the West, but he was embarrassed when Brazil — a country he has courted — offered asylum to Ashtiani. Suddenly, Ashtiani “confessed” to murder and may now face execution by hanging instead of stoning. Fortunately, international attention is now focused on the case.

More recently, a letter was smuggled out of Evin prison that came from prominent human rights activist Abdollah Momeni and was addressed to Iran’s Supreme Leader Ali Khamenei. It described horrific torture. You can read the entire text at www.iranhumanrights.org, but it takes a strong stomach.

Momeni details savage beatings and near-suffocation, confinement for months in a coffin-like cell, having his head held in a toilet bowl full of feces, and threats of rape or imminent execution. He was finally forced into a false confession at a sham trial.

“By addressing this letter to Khamenei, Momeni has challenged leaders from Khamenei to Ahmadinejad” to investigate abuses, said Hadi Ghaemi, head of the International Campaign for Human Rights in Iran. “Now they cannot say they were unaware what was happening in Iranian prisons.” If there is no response, Ghaemi added, it will be clear that “these systematic and inhumane methods … are sanctioned by them.”

Ghaemi called on U.N. Secretary General Ban Ki-moon to press for independent U.N. monitoring of Iran’s human rights record.

Of course, Iranian officials regularly deny that they torture prisoners or coerce confessions. But in this globalized world, they can’t keep their behavior secret.

The world is watching: Will Iran stone Ashtiani to death or hang her? Will Khamenei investigate the abuse of Momeni and other prisoners? Will the Islamic republic stage a show trial of Fattal and Bauer, knowing they are innocent? Or will it act like a responsible international player and set them free?

Nothing will discredit Ahmadinejad’s pretensions more than further show trials in violation of all norms of international behavior. Iran’s moral standing depends on what it does, not on his self-aggrandizing words.