At the moment, several conflicts are being fought simultaneously in Syria. The civil war began more than two years ago as a power struggle between the government and opposition forces. But it didn't take long for other states to get into the mix, turning the internal fight into a regional and international struggle for influence.

In addition to Western countries as well as Russia and Turkey, neighboring countries like Iran, Saudi Arabia and Qatar have become involved. The three countries are fighting a proxy war for regional dominance. The religious division between Sunnis, Shiites and Alawites only plays a minor role.

Syria is a strategically important country for Iran. The regime of President Bashar al-Assad is Tehran's only ally in the Arab world. In addition, Syria is an important link to the pro-Iranian Hezbollah movement in Lebanon, said Stephan Rosiny, a Middle East expert at the Hamburg-based GIGA Institute for Middle East Studies. Speaking to DW, he added that Tehran, Damascus and Hezbollah see themselves as the resistance front against Israeli and Western interests in the region.

Fall of Syrian regime would be a blow to Iran

Saudi Arabia and Qatar, on the other hand, want to curb Iran's attempts at regional domination and thereby increase their own influence. An overthrow of the Assad government would be a major blow for Iran, and so the two monarchies have been quite openly backing the Syrian opposition. And not just in Syria - they have even been promoting anti-Iranian groups in Lebanon and Iraq.

According to Rosiny, though, both countries have pursued different strategies. For decades, Saudi Arabia had lent its support to radical Salafist groups, but ever since bad experiences with al Qaeda and Saudi volunteer fighters in Afghanistan, the monarchy has become more cautious.

On their return after the fighting, many veterans considered the Saudi state as their new enemy. As a result, many Saudis have gone to fight as volunteers in Syria.

"That's why Saudi Arabia has somewhat moderated its support of these groups," said Rosiny. Qatar, in comparison, has been less indiscriminate and has partially supported radical groups.

The Syrian opposition has opened its first embassy in Qatar

"The Qataris are new to the game, and they don't have the experience of sending fighters and light weapons into a country where it could hurt them," said Mehran Kamrava, a political scientist at the Georgetown University School of Foreign Service in Qatar. For that reason, support from Qatar has been less restrained.

Proof of the weapons shipments and cash flows to Syria's warring parties, however, is not so easy to find. Iran has apparently been sending massive aid to the beleaguered regime in Damascus, with the Syrian rebels accusing Tehran of sending its allies weapons and members of its elite Revolutionary Guards.

In addition, the pro-Iranian Hezbollah has intervened on the side of the Syrian army in the fight against the predominantly Sunni rebels.

Gulf states appear to be providing weapons on a large scale

On the opposite side of the Gulf, countries have apparently not paid much mind to the arms embargo. According to Western media reports, Qatar is said to have paid hundreds of millions of US dollars to the Syrian opposition. Moreover, at least a dozen planes loaded with weapons and ammunition are said to have been delivered to the rebels via Turkey.

According to US media reports, Saudi Arabia financed the purchase of, among other things, Croatian weapons which were then sent to Syria via Jordan. Earlier this year, former intelligence chief Turki al-Faisal said: "I suppose we'll send weapons. If not, that would be a terrible mistake for us." The Gulf states have yet to deliver heavy weapons or high-tech equipment such as anti-aircraft missiles to the fractious opposition.

Iran is said to have sent its Revolutionary Guards to Syria

In this respect, Saudi Arabia and Qatar have seemingly been following similar policies to Western countries. But Rosiny is skeptical of this alliance, saying it would be questionable to be in the same boat as the two Gulf monarchies as these states are by no means just stabilizing forces in the region.

"Saudi Arabia is certainly less interested in the democratization of Syria. They showed this in neighboring Bahrain," said Rosiny. In 2011, Saudi Arabia supplied Bahrain with troop support after the revolt against the Bahraini royal family reached threatening proportions.

The power struggle between Iran, Saudi Arabia and Qatar runs along religious fault lines. On one side are the conservative Sunni monarchies that have backed the predominantly Sunni opponents of the Assad regime. On the other, the Shiite Republic of Iran has supported the Syrian government in Damascus, along with the Alawites, the latter once originating in Shiite Islam.

Even so, Rosiny and Kamrava do not view the proxy conflict in Syria as being primarily a struggle between Sunnis and Shiites. "This is an unintended consequence of this conflict," said Kamrava. Though the Saudis and the Qataris may view the conflict through the prism of religion, the primary reason for their support is their own strategic goals.