Qatar has for years played the role of the Middle East peace broker in a bid to free hostages and secure peace agreements from Sudan to Somalia
To its foes, Qatar's deal-making with armed groups is reckless grandstanding that helps destabilise the Middle East.
To its friends, the network of Islamist contacts Doha has built in the process may prove crucial to mediating peace in regional hotspots, including in Syria.
On one thing both supporters and detractors agree: no state has made more of an effort to open channels of communication with militants among Syrian rebels.
Qatar has for years played the role of the Middle East peace broker, using its gas riches and wide-ranging political ties in a policy of international self-promotion to free hostages and secure peace agreements from Sudan to Somalia.
As Qatari Foreign Minister Khaled al-Attiya explained it on Thursday in a speech ahead of National Day: "Diplomacy is a tool we use to empower people and spread security... while taking care not to interfere in the internal affairs of other states."
Others might disagree. A turn in 2011 towards a more interventionist foreign policy supporting Arab Spring revolts and bankrolling Islamist influence has irritated conservative neighbors.
The risks were highlighted on Wednesday, when gunmen kidnapped 26 Qatari nationals from a desert hunting camp in southern Iraq, following a pattern in recent years of insurgents in Iraq and Syria making millions by kidnapping scores of journalists, soldiers and politicians.
The identities of Wednesday's kidnappers are not known but Shi'ite militias, who populate the area where the Qataris were seized, have accused Doha of meddling in their nation's affairs.
Critics fear Qatar's policies embolden jihadists whose ultimate aims, if not methods, look similar to those of Islamic State. But others have hailed its role in brokering deals of a kind that may be needed in Syria.
Efforts to end the war have gathered pace in recent weeks: Major powers including Qatar are due to meet in New York on Friday after earlier talks in Vienna. Rebel groups who met in Riyadh on Thursday chose a former prime minister to represent them in the peace process.
One player that has severely tested the effectiveness of Qatar's strategy is the Nusra Front, al Qaeda's Syrian affiliate, which, like Islamic State, is widely regarded as unacceptable to all parties in the Syrian conflict and was not invited to Riyadh.
Doha, which sees Nusra Front as one of the most effective fighting forces in Syria, has tried to push the group to adopt a more moderate Islamist platform in the hope it could eventually split from al Qaeda and be supplied with arms.
That hope remains unfulfilled. The group's leader, Abu Mohamad al-Golani, said in remarks broadcast on Saturday he remained loyal to al Qaeda and had no interest in joining the process in Riyadh which he called a "treason" against Syrian youth.
Nusra on Dec. 1 released 16 Lebanese soldiers and policemen as part of a prisoner exchange brokered by Qatar, a deal that a Saudi-owned news site said included a $25 million cash payment, which Qatar has denied.
Diplomats and analysts warn that such deals with Nusra could strengthen the group, which in addition to battling Assad is calling for the establishment of an Islamic government in Syria.
"Nusra wants recognition, they want to be seen both in and outside Syria as a partner so they can establish a lasting foothold in the country," said Marwan Shehada, a Jordanian expert on Islamist groups.
"They hope to be embraced by the Qataris in the same way other groups have. Hostage negotiations are a way to raise money but also to boost prestige."
Rebranding the Nusra Front to remove legal obstacles preventing the West from supporting it is an idea that Qatar may once have entertained, but has since dropped, analysts say.
"Any attempt by Qatar to moderate Nusra has completely failed," said analyst Ghanem Nuseibeh of Cornerstone Global Associates. "Nusra are al Qaeda. No matter how many prisoner exchanges they do, they will never be accepted by the West as a legitimate actor."
Possibly in recognition of the limits to its ambitions, the interventionist aspect of Qatar's foreign policy has been dialled down over the past year. But it still keeps in contact with a wide variety of groups.
Jean-Marc Rickli, an assistant professor at King's College London, said it was important to differentiate between Qatar's active support for groups in Syria and its policy of maintaining a channel of communication.
"Whether you like Qatar's policies or not, they do play a role that is unique," he said.
"At some point in Syria there will be a need for mediating between all these groups. Considering the lack of success in fighting al Qaeda over the last fifteen years, a day will come when people ask 'what do we do with Nusra?' Having a state that can talk to them is important."