President Obama has his hands full dealing with Russia. However, high on his agenda should be the release of Mikhail Khodorkovsky, Moscow's most famous prisoner.

Success there would demonstrate the administration's ability to promote freedom in Russia and around the world. It even might encourage the freeing of other political prisoners and a new wave of reforms that would make Russia a better partner for the U.S.

Who is Mr. Khodorkovsky? Until the fall of 2003, he was the richest man in Russia, owning a majority stake in the Yukos Oil Co. In just four years, Mr. Khodorkovsky transformed Yukos from a failing, state-owned behemoth into Russia's best-managed energy enterprise. Its stock price skyrocketed 4,400 percent.

But after butting heads with then-President Vladimir Putin, Mr. Khodorkovsky was arrested in 2003 on tax-evasion charges. His real crime, however, was his desire for political independence from the Kremlin kleptocracy. "I want to be a free man in a free country," he said. That was his greatest mistake.

Mr. Khodorkovsky could have emigrated to the West, but he loved his country. He decided to stay and fight. He financially supported democratic opposition parties such as Yabloko and Union of Right Forces (now barred from the Russian Parliament). His "Open Russia" charity spent $100 million a year on Internet and education projects.

On the business front, he proposed an oil pipeline to China and another to the Arctic port of Murmansk. It was all too much for Mr. Putin and the other ex-KGB strongmen who wanted to control Russia's oil sector and pocket billion-dollar profits for themselves.

Relations with Mr. Putin deteriorated irretrievably after Mr. Khodorkovsky publicly questioned him about Kremlin corruption. Mr. Putin's cronies arranged for the entrepreneur's arrest, then expropriated Yukos. The company's tens of thousands of shareholders received no compensation.

Mr. Khodorkovsky, however, received a nine-year sentence even though the prosecution's case fell apart. Both the Russian tax authorities and international auditing firms certified Yukos had paid all the taxes.

Today, Mr. Khodorkovsky and his partner, Platon Lebedev, face a second trial on trumped-up charges of "embezzling" oil belonging to Yukos. If convicted, they will spend the rest of their lives in the modern gulag.

Moscow sorely needs talents like Mr. Khodorkovsky and his programs to reform Russia's economy. The old, commodity-based economy has reached a dead end. To continue growing, Russia must pursue a post-industrial model. That will require enlightened leadership, foreign investment and management skills - the skill set epitomized by Mr. Khodorkovsky.

President Dmitry Medvedev recognizes this. He regularly touts modernization and innovation while denouncing "legal nihilism," police brutality and corruption. Yet the hounding of Mr. Khodorkovsky exemplifies what's wrong with Russia today.

Pardoning Mr. Khodorkovsky would be a truly dramatic gesture for Mr. Medvedev - and an enormously helpful one. It would open a new page in politics - just as Andrei Sakharov's 1987 release from exile in Gorky signaled new freedom in the USSR.

Yet the decision to pardon Mr. Khodorkovsky is Mr. Putin's, not Mr. Medvedev's. And Mr. Putin's closest friends are the same people who orchestrated the demise of Yukos, the first trial and, now, the second one.

President Obama already has his hands full with Moscow. He needs to ensure that Russia lets the United States and NATO supply our troops in Afghanistan. He wants to wrap up arms-control negotiations soon. And he wants Russia to support crippling sanctions against Iran in the United Nations.

But Mr. Obama also needs to show consistency on Mr. Khodorkovsky. In 2005, he introduced Senate Resolution 322, stating that Russia "did not accord Khodorkovsky fair transparent and impartial treatment." He brought up the issue again in his visit to Russia last summer.

He is not alone. The U.S. Senate raised the issue again last year, as did the German, British, Italian and European parliaments.

Mr. Obama needs to tell his Russian counterparts that they cannot flout the will of international public opinion.

Ariel Cohen is a senior research fellow at the Heritage Foundation's Institute for International Studies.