The sentencing of a dissident to 11 years in jail on Christmas Day is the latest brick in the wall that the Chinese government is erecting in an effort to insulate that nation from the tide of history. Mr. Liu Xiaobo's crime? Being one of more than 300 people who signed Charter 08, a direct appeal for political liberalization in China. The verdict is a reminder of the intolerance and brute force that are the cornerstones of the Chinese political system.

Mr. Liu is no stranger to controversy. He was a literature professor and writer who joined the protesters who occupied Tiananmen Square in the spring of 1989. As the end neared and the bloody denouement became all but inevitable, he encouraged the demonstrators to leave the square peacefully. After the crackdown, he was detained and held for 21 months without trial. In 1996, he was sent to a labor camp for three years after publicly calling for the release of those imprisoned for joining the protests.

Fired from his teaching job, he became a trenchant essayist and social critic, penning numerous analyses of the Chinese political and social system and posting them on the Internet. What most infuriated the Chinese leadership was his authorship of Charter 08, a document modeled after Charter 77, a Cold War appeal for reform by Czechoslovakian dissidents. Charter 08 called for political liberalization, rule of law and the right to genuinely free speech and other human rights. More than 300 people, including some of the country's best-known intellectuals and human rights activists, originally signed the charter. After being posted on the Internet — and despite being subject to the censorship imposed by the "Great Firewall of China" — the petition attracted an estimated 10,000 signatures.