A U.N. Commission of Inquiry this week laid out a case that the Syrian government, pro-government militia, and to a lesser degree, armed opposition forces, have engaged in massive rights abuses amounting to crimes against humanity and war crimes.
So what's the likelihood the President Bashar al-Assad and his military planners will ever have their day in court at The Hague?
For the time being, it looks pretty slim.
The Geneva-based commission, headed by Brazilian diplomat and lawyer Paulo Sergio Pinheiro, has issued no call for prosecution by the International Criminal Court, which investigated and issue warrants for other world leaders, including the late Libyan leader Muammar al-Qaddafi and Sudanese President Omar al-Bashir.
Instead, Pinheiro has kicked the ball over to the U.N. Security Council to decide how to hold the Syrian perpetrators to account and will hand a list of suspected abusers to the High Commissioner for Human Rights, where they will lie in a sealed envelope awaiting a possible decision by some as yet undetermined court to prosecute.
Meanwhile, there remain serious hurdles to prosecution.
Syria has never ratified the treaty, known as the Rome Statute, which established the International Criminal Court (ICC), placing the government beyond the court's reach.
The treaty includes a provision that allows the U.N. Security Council to initiate an ICC investigation. But it is almost unthinkable that the 15-nation council, where Syria's allies Russia and China wield veto power, would authorize an ICC investigation into Assad's alleged crimes, or those of the armed opposition for that matter.
There appears to be little appetite in the Security Council for establishing a temporary court, as it did in the past to prosecute crimes in Bosnia, Rwanda, and Sierra Leone.
Last April, Aryeh Neier, who recently stepped down as president of the Open Society Institute, proposed the establishment of an Arab war crimes court, authorized by the Arab League, to prosecute Syrian war criminals. But the idea has gained little traction.
European courts that assert universal jurisdiction over large-scale crimes, including genocide or war crimes, could prosecute Syrians responsible for murdering nationals from their countries, but they will be hard pressed to get them to surrender to a court in London, Paris, or Madrid.
Pinheiro, meanwhile, has claimed that his mandate does not give him the authority to recommend the U.N. Security Council authorize and investigation by the International Criminal Court, according to court advocates.
But ICC advocates contend that he not only has the authority but the obligation to do so. A call for a referral from the Security Council, they say, will add to the international pressure on Russia and China to ensure rights violators are held to account.
"Given the scale of the crimes it would seem incumbent upon the commission to make a recommendation to the council [for an ICC prosecution] regardless of its viability," said Richard Dicker, an advocate of the ICC at Human Rights Watch. "A referral to the ICC should be very high on the list of recommendations. It's an important statement of principle. There's a second more practical factor: what looks like a fixed situation today, in terms of obstacles at the council, could change in the future."
In August 2011, the U.N. Human Rights Council established a commission of inquiry to investigate allegations of human rights abuses in Syria dating back to March 2011 -- shortly after the government mounted a bloody crackdown on anti-government protesters.
It has since produced three written reports detailing abuses by both government-backed forces and rebels. On Wednesday, the commission concluded that there are "reasonable grounds" to assert that the Syrian government, pro-government Shabbiha militia, and armed anti-government forces committed war crimes and crimes against humanity during the country's 17-month long uprising.
But it found that the most egregious abuses were carried out by forces loyal Assad and acting "with the knowledge, or at the behest, of the highest level of the government."
The commission's findings confirm its previous claims that the warring parties committed crimes against humanity during a conflict that the U.N. says has led to the deaths of more than 14,000 people. But this week's reports marked the first time it accused the various groups with war crimes and other violations of international humanitarian and human rights law.
The commission, which was established in August 2011 by the U.N. Human Rights Council, particularly blamed the Syrian government and the Shabbiha for carrying out the large-scale killing of Syrian civilians in the town of Al Houla, dismissing government claims that the killings were carried out by anti-government forces.
More than 100 civilians were killed on May 25 at Al Houla in a gruesome military-backed operation that marked a sharp escalation in the violence in Syria.
"The commission confirms its previous finding that violations were committed pursuant to State policy," reads the report. The commission also "found reasonable grounds" to believe anti-government opposition forces committed war crimes, including murder and extrajudicial executions and torture, but that the abuses "did not reach the gravity, frequency and scale of those committed by government forces and the Shabbiha."
But the commission provides no specific proposal for an independent international prosecution.
Instead, it calls on the Syrian government to conduct its own investigation into human rights violations that is has ordered, and to hold perpetrators accountable. It also recommends that Human Rights Council beef up its reporting presence in Syria, and transmit its findings "to the Secretary General for the attention of the Security Council so appropriate action may be taken."
Thus, the prospect for prosecution remains uncertain. Moreover, the commission is due to close in September.
"The options are not good," said James Goldston, executive director of the Justice Initiative at the Open Society. But Goldston said he was "puzzled" by Pinheiro's decision not to explicitly call for an ICC role in Syria, noting that the U.N. High Commissioner for Human Rights, Navi Pillay, and more than 20 other countries in the Human Rights Council, have. "It can only help if the independent commission would add its voice."
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Longtime Washington Post correspondent Colum Lynch reports on all things United Nations for Turtle Bay.