A gruesome snuff video that has garnered more than 180,000 views on YouTube underlines just how grim the Syrian conflict has become.
This video appears to document one of the worst kinds of war crimes: The summary executions of wounded men. (Warning: The scenes are extremely graphic.)
Several paramilitaries in battle fatigues armed with automatic weapons -- some speaking Arabic in distinctive Lebanese accents -- pull wounded men out of the back of a van and drop them on to the ground, then shoot them in their heads at point-blank range.
As they shoot their victims, some of the paramilitaries seem almost giddy with excitement.
A man who appears to be their commander admonishes his men, "Come on guys, we are here to carry out our duties not to seek revenge on our own. This is unacceptable."
One of the paramilitaries smilingly replies, "But we are killing them in God's cause, only in God's cause."
The wounded men lying on the ground awaiting their deaths repeat religious phrases that are commonly said just before death. They all appear to be civilians.
There has been much analysis of the al Qaeda-aligned groups in Syria fighting the Assad regime that have recruited thousands of foreign fighters from around the Arab world and a smaller number from the West, but there has been far less discussion of the Shiite militias in Syria that have recruited foreign fighters from Iraq as well as from Lebanese Hezbollah, all of whom are fighting to support Syrian President Bashar al-Assad.
Barak Barfi, an American journalist who is a fellow at the New America Foundation and who has reported inside Syria for many months, says that one of the executioners in the videotape is wearing a distinctive yellow armband that Hezbollah fighters wear. Barfi says, "This appears to be a Hezbollah video, though we cannot conclude this with high confidence."
Similarly, Augustus Richard Norton, professor of international relations at Boston University and the author of an authoritative study of Hezbollah, says, "The only identifying marks on the uniforms are yellow ribbons, which, in theory, would identify them as Hezbollahis."
Randa Slim, also a fellow at the New America Foundation and a scholar at the Middle East Institute who is writing a book about Hezbollah, says that based on the accents of the Arabic-speaking executioners the video shows Syrians as well as fighters from Iraq and Lebanon.
Slim cautions, however, that the paramilitaries conducting the executions could well be members of an Alawite militia made up mostly of Syrians who have been trained by Hezbollah, but that are not part of Hezbollah itself.
Phillip Smyth, a researcher at the University of Maryland who specializes in Shiite militias operating in Syria, says that the fighters are likely from Hezbollah as they speak in a Lebanese accent and when they perform the executions they mention a religious edict handed down by a key Hezbollah religious guide.
Oubai Shahbandar is a Syrian-American who worked at the Pentagon for much of the past decade as a Middle East analyst, including a stint on General David Petraeus' staff during the Iraq War, and is now a vice president at the Syrian Support Group, which supports "moderate elements of Syria's armed opposition."
Shahbandar has been tracking Hezbollah since 2007 and he asserts that the executioners in the video are definitely from Hezbollah and that the video itself was shot in Homs province in western Syria.
An analysis done by CNN's International desk confirms that the dialect spoken by the executioners in the videotape is Lebanese Arabic and they can be heard shouting "Fi Sabil Allah," an Arabic phrase that means "in God's cause," an expression commonly used by Hezbollah fighters on the battlefield. The international desk's analysis points out that the yellow and green ribbons tied to the fighters' uniforms appear to mark them as Hezbollah fighters.
As is now well known, many of the players in the Syrian conflict, including most prominently the Assad regime itself, have committed war crimes against civilians.
On Friday, Human Rights Watch released a report documenting a massacre on August 4 that was perpetrated by two al Qaeda-aligned Sunni militant groups, the Islamic State of Iraq and Sham and Jabhat al-Nusra.
The massacre took place in the coastal region of Latakia in a number of Alawite villages supportive of the Assad regime. According to the report "Eight survivors and witnesses described how opposition forces executed residents and opened fire on civilians, sometimes killing or attempting to kill entire families who were either in their homes unarmed or fleeing from the attack, and at other times killing adult male family members, and holding the female relatives and children hostage. "
Human Rights Watch collected the names of 190 civilians who were killed in these attacks, including 57 women and at least 18 children and 14 elderly men.
While the world in the past few weeks has been distracted by the U.S. government shutdown and the brutal attack on the mall in Kenya by an al Qaeda affiliate that left at least 67 dead, the Syrian war has ground on.
It is a war that has now claimed as many as 120,000 lives.
Four of those deaths are documented in the appalling videotape of the Shiite paramilitaries gleefully executing wounded men who appear to be civilians. And the deaths of 190 civilians killed by Sunni militias in August are documented in great detail in the Human Rights Watch report that was released Friday.
Just when you thought the Syrian civil war couldn't get any worse, it does.
Peter Bergen is CNN's national security analyst, a director at the New America Foundation and the author of Manhunt: The Ten-Year Search for bin Laden -- From 9/11 to Abbottabad. Jennifer Rowland is a graduate student at Harvard University's Kennedy School.