The conflict in Syria may be first and foremost a civil war, pitting the Shiite-dominated regime of President Bashar Assad against mostly Sunni insurgents. But the region's turbulent geopolitics have turned it into a proxy fight that has drawn in the rest of the region as well as the U.S and other global powers.
"This has become not just a war within Syria," Robert Malley, the program director for Middle East and North Africa for the International Crisis Group, told NPR's Fresh Air earlier this month. "It has become a regional, sectarian civil war. Perhaps the best way to put it is to say that what was a war in Syria with regional spillover has now become a regional war with a Syrian focus."
On the ground in Syria, the military and pro-regime militiamen called Shabiha are arrayed against the main rebel groups, known collectively as the Free Syrian Army and organized under the umbrella of the Supreme Military Council. Smaller rebel groups — including the Islamic extremist group Jabhat al-Nusra (deemed a terrorist organization by the U.S.) — and foreign fighters and jihadist veterans from Iraq and Afghanistan are also battling the Assad regime.
Now, with Washington's assertion that the Syrian regime has crossed a "red line" by using chemical weapons against the rebels, the U.S. is prepared to give military support to the insurgents. But competing outside interests — notably Russia and Iran — could complicate any American effort to step up aid to the rebels.
Below, we outline some of the stakeholders and what's at stake for them:
Iran and Syria have been allied since 1979, and since the start of the Syrian civil war, Tehran and Iranian-backed Hezbollah militants have actively supported the Assad regime and helped it regain ground against rebels.
Jubin Goodarzi of the United States Institute of Peace writes:
"The two regimes share common traits. They are both authoritarian and defiantly independent, even at a political or economic cost. Iran is predominantly Shiite. Although Syria is predominantly Sunni Muslim, its ruling family is Alawite, a Shiite sect."
Mustafa Alani, director of security and defense at the Dubai-based Gulf Research Center, told The Washington Post:
"If Iran wins this conflict and the Syrian regime survives, Iran's interventionist policy will become wider and its credibility will be enhanced. This is an Iranian fight. It is no longer a Syrian one," he said. "The issue is hegemony in the region."
"If Assad falls, Iran will be concerned about loss of influence in both Lebanon and Syria. ... Iran, like Russia, knows that if Assad is toppled, or if his regime loses control in Damascus, things could change very fast. The regime has remained strong for so long because of its apparatus of control and repression, particularly in the capital. Once that crumbles, a new chapter will have begun in Syria. But many fear this new phase could be just as violent."
For Tehran, propping up Assad "gives the mullahs access to an unmatched, dominating presence in the Levant — that stretch of geography from Israel's southern border to eastern Turkey — that touches every front-line Mideast country," according to Foreign Policy:
"As well, a Syrian-Iranian victory offers Iran an outlet to the Mediterranean and access to the near-obsolete Russian naval facility at Tartus, a base that has begun to figure again in Russian plans for its navy. Wars never really return to the status quo ante, and a victory for the Assad regime, and a concomitant rise in influence and access for Iran to this strategic geography, changes for the foreseeable future the power balances and political relationships in the region and perhaps the world."
In August 2011, a few months after the uprising against Assad began, President Obama said the regime must go. But until this week, the administration seemed content to let the situation play out, despite the carnage — a death toll estimated to be at least 93,000.
"The United States — the administration — has a side," Malley of the International Crisis Group told Fresh Air. "It has affinities with the opposition. It doesn't want to see the regime continue. ... The question in my mind, one of the things that we have to bear in mind, is we might have a stake in whether the Assad regime continues or not, but do we have a stake — or should we have a stake — in the broader Sunni-Shiite confrontation? Should we take sides in this religious war, which it has now become?"
"On strategic grounds as well, it's in the national interest of the United States to break that axis, that alliance between Iran, the Assad regime and Hezbollah," he said. "So, both in terms of American values and the American national interest, I think the U.S. should do more than it is doing."
However, Daniel W. Drezner, writing in Foreign Policy, says there's a more pragmatic reason for U.S. interests:
"This is simply the next iteration of the unspoken, brutally realpolitik policy towards Syria that's been going on for the past two years. To recap, the goal of that policy is to ensnare Iran and Hezbollah into a protracted, resource-draining civil war, with as minimal costs as possible. This is exactly what the last two years have accomplished ... at an appalling toll in lives lost.
"This policy doesn't require any course correction... so long as rebels are holding their own or winning. A faltering Assad simply forces Iran et al into doubling down and committing even more resources. A faltering rebel movement, on the other hand, does require some external support, lest the Iranians actually win the conflict."
Israel and Syria remain technically in a state of war but have maintained relative calm along their 43-mile cease-fire line straddling the Golan Heights. Assad, like his father, Hafez, has declared himself an implacable enemy of Israel.
Even so, Al-Jazeera notes, "the reality is that since end of the Yom Kippur War in 1973, the Syrian front has been one of Israel's quietest."
It goes on to say:
"Israel has been particularly unnerved by the collapse of stability in the Golan Heights, which it occupies. The UN force (UNDOF) is virtually confined to its base, and a number of Syrian opposition groups have been firing towards Israel."
One Israeli official was quoted by The New York Times as saying last month that he thought Israel was being "very measured and very cautious in a very volatile situation."
The Times article cites "several Israelis who follow Syria closely" as saying:
"Israeli security forces had already been quietly working with [Druse] villagers who support neither the government nor the rebels, supplying moderate humanitarian aid and maintaining intense intelligence activity.
"But they said any notion of arming such villagers was far off if not far-fetched, noting that the main Druse leadership in Syria has so far stayed steadfastly out of the conflict."
The wealthy Gulf country of Qatar has been playing a wider role as a U.S. partner since the Arab Spring uprisings, and has sought to fill a vacuum left by the collapse of Egyptian President Hosni Mubarak's regime, Tamara Wittes, director of the Saban Center for Middle East Policy at the Brookings Institution, told NPR.
"One of the consequences of the fall of Mubarak is that the U.S. lost in a way its central diplomatic partner in the Arab world. In many ways, the Qataris stepped up to play that role, in the Arab League, for example, on Libya and then on Syria," Wittes said.
Foreign Policy notes:
"Although the Syrian rebels received military aid from various countries and private donors, Qatar initially emerged as the main sponsor of the opposition. Its alliance with Syria's Muslim Brotherhood helped it control the political opposition and the armed rebels' most prominent factions."
Riyadh has increasingly taken over Qatar's role as the primary benefactor of the Syrian rebels, writes Foreign Policy.
"Under increased pressure from the United States, Qatar has recently handed over the 'Syrian dossier' to Saudi Arabia. Members of the Syrian opposition coalition made a two-day visit last month to Riyadh for the first time to coordinate with the Saudis. The opposition's delegates were asked by Riyadh to restructure the Syrian National Coalition, the umbrella group for the opposition, which they bitterly did three weeks later.
"In response, Saudi Arabia has stepped up its aid. Riyadh provided the rebels with 35 tons of weapons, though the kingdom failed to provide them with the better-quality arms the FSA's chief of staff had requested."
Moscow has been one of Syria's closest allies since the days of the Cold War, when the then-Soviet Union sought close ties with Arab countries as a counterbalance to the U.S.-Israel alliance. Russia has long supplied Syria with arms and recently has pledged to send anti-aircraft missiles and advanced fighters to Damascus, presumably in case the U.S. and its allies should decide to impose a no-fly zone (although the timing of any such deliveries might prove problematic).
On Saturday, Russia's Foreign Minister Sergei Lavrov said evidence cited by the U.S. for Syria's use of chemical weapons is not reliable. Lavrov also warned that imposing a no-fly zone over Syria would violate international law.
"Russia has military personnel inside Syria at its Tartus naval base on the Mediterranean Sea. Despite a number of evacuation missions, there are still believed to be many Russian citizens living in Syria. Getting all of their citizens out in the event of a decisive change in Syria will be a key priority for Russia."
The International Crisis Group's Malley told Fresh Air: "[I]f Assad has Russia completely on his side ... he won't budge. There's no reason for him to budge. You could say the same about the opposition, but clearly it's the case of Assad if he feels that he has Russia — let alone Iran and Hezbollah — strongly backing him, he has no reason whatsoever to compromise. So there needs to be an understanding between Russia and the U.S. at a minimum. Ideally, it would involve others as well, but let's start with what is more manageable, and even that's hard and hasn't been achieved yet."