The leaders of Russia, Iran and Turkey met in Sochi to discuss ways of ending the six-years-long war in Syria, with representatives from the United States notably excluded. It comes as members of the fractured Syrian opposition convened in Saudi Arabia in a bid to form a united front ahead of prospective peace talks in Geneva in December. “Militants in Syria have received a decisive blow and there is a real chance to put an end to the civil war that has raged for many years,” Russian President Vladimir Putin asserted at the start of the tripartite summit being attended by Iranian President Hassan Rouhani and his Turkish counterpart Recep Tayyip Erdogan. A major sticking point remains the fate of Syrian chief Bashar al-Assad, who made a surprise trip to Russia earlier this week for talks with Putin. While Assad reportedly pledged to implement constitutional reforms and hold new elections under United Nations supervision, the Syrian opposition has insisted from the beginning on Assad’s removal as a precondition to any formal negotiations. Turkey likewise long opposed the Syrian regime, which is supported by Moscow and Tehran, although Erdogan has since moderated his position over fears that Ankara’s absence from the peace process could lead to the formation of an independent Kurdish state in northern Syria, along Turkey’s border. The three countries have been instrumental in brokering truce agreements in four areas in Syria, helping to reduce hostilities with the ultimate goal of forging a deal to end the conflict. Washington, however, remains the wild card, as U.S. military officials have recently indicated that they are prepared to keep troops in Syria over the long term, a move that Putin has strongly criticized. The American military backs the Kurdish-majority Syrian Democratic Forces, which spearheaded the effort to oust the Islamic State from Raqqa, the former capital of the terror group’s so-called caliphate.