LAST MONTH, Syria's leading dissident went to jail again. Riad Seif's arrest didn't come as much of a surprise; the former member of parliament and longtime human rights advocate had devoted much of the past two decades to criticizing the authoritarian Assad regime. He was released only two years ago after spending five years in prison for organizing meetings to promote democratic change. This time, Seif's transgression was attending a meeting of pro-democracy opposition groups.

Detentions of reformers and democracy and human rights advocates are not typically news in Syria. Neither are the allegations of physical abuse that several of Seif's incarcerated pro-democracy colleagues reported to Human Rights Watch. But Seif's most recent arrest is newsworthy because it essentially constitutes a death sentence for the 61 year old activist; not only does Seif suffer from diabetes and a heart condition, last year he was diagnosed with prostate cancer.

At the risk of eulogizing Seif prematurely, his accomplishments in Syria--and his perseverance--have been nothing short of remarkable. A garment trader by profession, Seif's business acumen made him prosperous and would have assured him and his family a life of material comfort had he not entered politics.

Seif's problems started in 1994 when he was elected to a four-year term in parliament. His business-oriented election campaign platform was innocuous and of little apparent concern to the regime. Once in parliament, however, Seif agitated for economic and fiscal reform and launched a campaign against corruption, which he termed "the source of all the evils. . . afflicting the Syrian people." Things went south from there.

In August 1996, Seif's 21-year-old son Iyad died under what he describes as "mysterious circumstances." Then, after Seif published a high-profile study on economic stagnation in Syria, the Ministry of Finance charged him with tax evasion and targeted his financial assets. Government fines in excess of $2 million essentially bankrupted the reformer.

Still, Seif soldiered on and was reelected to a second term in 1998. In parliament, he continued to focus on issues of transparency and corruption, most famously the ubiquitous phenomenon of mobile phone contract monopolies granted to regime cronies. This particular quest for transparency implicated members of the regime's inner circle including Rami Makhlouf (a cousin of the Assads), clearly hitting a nerve. Tempting the fates, he also began establishing organizations dedicated to increasing civil consciousness. In 1999, his role in establishing one such organization--the "Friends of Civil Society Forum"--earned him an audience with the feared Syrian Vice President Abdul Halim Khaddam.

The regime subsequently denied the forum a license, a prerequisite for large gatherings in the repressive state, but Seif nevertheless convened the group and its better known successor organization, the "National Dialogue Forum," further angering the regime.

With the onset of the brief period of glasnost known as "Damascus Spring," which commenced upon Bashar Assad's anointment as president in 2000, Seif's pro-democracy political reform activities increased: there were more meetings and forums, and even talk of establishing a political party called the Social Peace Movement Party. Then he stepped up his attacks on the government from his perch in parliament. A February 2000 speech to the prime minister and cabinet, which Seif wrote about in 2007, provides a good sense of how far he was pushing the envelope:

"breaking the [Baath party] political monopoly is a necessary condition to implement the principle of transparency . . . any monopoly cannot help but breed sterility and stop development and growth. It is not possible to separate economics from politics . . . the political monopoly necessarily results in other economic, cultural, and educational monopolies . . . "

The Baathist majority struck Seif's statement from the parliamentary record, but his comments were not forgotten. When "Damascus Spring" ended in February 2001, the regime moved precipitously to strip Seif of his parliamentary immunity. Arrests of reformers commenced that summer.

But even from jail, Seif continued to push for reform in Syria. Perhaps his crowning achievement in this regard came in 2005, when he co-authored from Adra prison the "Damascus Declaration," which among other things demanded an end to the Assad regime and Baath party monopoly of power, a suspension of the Emergency Law, and the drafting of a new Syrian constitution.

When he was arrested last week, Seif was participating in a meeting of the Damascus Declaration National Council, an umbrella organization dedicated to the implementation of these reforms.

Not content with merely preventing Seif from seeking treatment abroad, the Assad regime has now seemingly condemned Syria's leading reformer to death behind bars. His incarceration is a strong message to would-be Syrian democrats. But it's also a clear message for Washington: the Assad regime is not interested in political liberalization. As the ongoing Syrian obstruction of Lebanese presidential elections would also suggest, the Assad regime's interventionist and destabilizing foreign policies are not up for discussion, either.

The Assad regime is unrepentant about Seif's unusually harsh treatment. Last week, Syrian Foreign Minister Walid Moualem had the temerity to blame the human rights community for the arrest. "The importance given to the case of Riad Seif," he told the Austrian Foreign Minister, "encouraged him to break the law."

For the Bush administration, Seif's death sentence should be a defining moment. Given the circumstances, last week's perfunctory condemnation calling on Syria to "modify its behavior . . . and provide its citizens with the rights they deserve," is not sufficient. Seif is far and away the most credible Syrian oppositionist. He is not particularly close to Washington--which has enhanced his local appeal--but administration concerns about undermining his position in Syria via a Western embrace ignore the urgency of the situation.

Like in Egypt, Washington has a choice to make. When Egyptian reformer Saad Eddin Ibrahim was arrested and convicted in 2002, the administration threatened to withhold $130 million in assistance. He was subsequently released. When reformist opposition presidential candidate Ayman Abdel Nour was arrested in 2005, the United States determined that the case was "an Egyptian issue," and he remains in prison to this day.

In recent years the policy of democracy promotion has gone by the wayside, but judging from the continued frequency of White House and State Department condemnations of Syria's atrocious human rights practices, the administration still considers the issue to be important. Given the lack of levers, pressuring Syria on human rights is clearly more difficult than it is in Egypt. Nevertheless, many in the administration acknowledge that Washington's response to the Abdel Nour case was not its finest hour.

With just eleven months left, time is running out for the administration and for Seif. Human Rights have always been an agenda item in Washington's bilateral representations to Damascus, albeit low on the list. The administration has a long range of grievances with Syria, ranging from its meddling in Lebanon and support for Hamas and Hizballah, to its continued meddling in Iraq. Among this crowded field, the administration would be well advised to raise the profile of it concerns regarding Syria's human rights practices.

Given the relentless repression of the Assad regime, when Seif is gone it could take years for another leader of his stature to emerge. In the absence of any real homegrown pro-democratic opposition, Damascus will face even fewer constraints to pursuing its pernicious policies at home and abroad.