When Syria's unrest began in the spring of 2011 with nationwide protests against President Bashar al-Assad's government, nobody could have guessed Syria would turn into a battlefield for multiple wars.
Here are five of the major struggles and conflicts of interests in Syria today.
International Coalition Vs. Global Jihadists
With U.S. President Barack Obama saying on September 10 that Washington is gathering an international coalition to roll back Islamic State militants in Syria and Iraq, both countries are about to become the arena for a major struggle between global jihadists and Western-backed forces.
The U.S. combat role will be limited to air strikes against Islamic State militants, while Saudi Arabia has agreed to host training camps for the moderate Syrian rebels who will do the fighting in Syria. Iraqi forces will do the fighting in Iraq.
Many of Washington's regional partners are already supporting rebel groups in Syria, varying from secular to Islamist. The trick will be to get everyone supporting the same groups and to ensure the war on the Islamic State militants does not drag in any of the neighboring states directly, creating a larger Mideast conflict.
Saudi Monarchy Vs. Saudi-Funded Jihadists
With Saudi Arabia's agreement to host training camps for rebel groups, Syria could become the arena for a struggle between two Saudi-supported forces.
According to "The New York Times," there are already Saudi-backed rebel groups in Syria "that include many hard-line Islamists, who often fight alongside militants loyal to Al-Qaeda." These groups receive financial support from private Saudi charitable foundations and, although Saudi Arabia officially bans its citizens from fighting in Syria, at least a thousand of them are believed to be doing so.
It could prove problematic for Riyadh if moderate rebel groups trained in Saudi Arabia were to find themselves on the opposite side of Saudi jihadists in the war on Islamic State militants. Such a proxy war could blow back home to threaten the Kingdom's stability.
Iran Vs. The Gulf States
Syria is already the arena for a proxy battle between Iran and the Gulf States that echoes the principal confessional split in Islam.
"Shi'ite Iran has already spent billions of dollars propping up Assad in what has turned into a sectarian proxy war with Sunni Arab states," Reuters reported recently. It quotes European and U.S. security officials as saying hundreds of Iranians are active in Syria advising, training and, in some cases, commanding Syrian government forces.
Iran supports the Assad regime in part because it is rooted in Syria's Alawite community, whose faith is an offshoot of Shi'ism. A close Iranian ally, Lebanon's Shi'ite Hizballah militia, intervenes directly in the fighting to bolster Assad's forces.
The Arab Gulf states support Sunni rebel groups because they regard Syria's civil war as a struggle by the country's majority Sunni population to shake off minority Shi'ite rule.
Saudi Arabia regards the stakes as particularly high because it sees Iran as a dangerous potential ally for its own restive minority Shi'ite population, which is located in the Kingdom's oil-rich southeast and complains of discrimination.
Syrian Secularist Rebels Vs. Islamic Extremist Rebels
The insurgency against Assad is handicapped by regular battles between rebel groups that have killed thousands of fighters this year alone.
Beginning in 2013, radical Islamic groups began making such rapid headway in clashes with the rival Western-leaning Free Syrian Army, that Western officials began to fear extreme Islamists would become the dominant insurgent power.
The planned counteroffensive against the Islamic State militant group could help reduce that danger.
Syrian Regime Vs. The Opposition
The biggest conflict in Syria remains the grinding war of attrition between Assad's forces and the hundreds of rebel groups fighting to topple him. That war, now 3 1/2 years old, accounts for the vast majority of the more than 190,000 people the UN says have been killed by fighting.
So far, the winner appears to be the Assad regime.
The "Los Angeles Times" wrote recently that "Assad has survived in large part because of disarray in the rebel ranks, including the rise of Islamist militants hostile to Syria's tradition of tolerant Islam; a steady flow of military and financial aid from Moscow and Tehran; and a revived Syrian military bolstered by local militiamen and Hizballah fighters from Lebanon."