By William Young, Special to CNN

Editor's note: William Young is a senior policy analyst at the nonprofit, nonpartisan RAND Corporation. He was formerly a senior officer with the Central Intelligence Agency with extensive experience in the Middle East. The views expressed are his own.

All roads lead to Damascus...and back out again. Financial and military aid flowing into Syria from Iran, Russia, Libya, Saudi Arabia, and other Arabian Gulf states aims to influence the outcome of the conflict between a loose confederation of rebel factions and the Bashar al-Assad regime. But this outside support could merely perpetuate the existing civil war and ignite larger regional hostilities between Sunni and Shia areas, reshaping the political geography of the Middle East.

In many ways, this is a continuation of the historical struggle between Sunni against Shia for dominance in the Islamic world, with Israel as another nearby target. Historical hatred between extremists on both sides of the conflict has already begun to spread fear and influence political sentiment north and east into Turkey and Iraq, west into Lebanon, Israel, and Palestine, and south into Jordan and the Arab Gulf. To understand these trends, it is important to ask: Who benefits from the conflict in Syria, and who loses?

The most obvious beneficiary is al Qaeda and affiliated groups. War zones and other ungoverned areas facilitate their contributions to insurgencies, provide safe havens, and expand their reach. The clear divide between Sunni and Shia in Syria offers a unique opportunity, however: a fight for control of Islam with historical antecedents in the centuries-old animosity between Salafists and Nusayris, or modern-day Alawites. The Alawites, the ruling minority under al-Assad, have much to lose in the struggle. The threat of retribution by those oppressed by the regime will likely galvanize commitment to the conflict. Iran also stands to benefit from either an unlikely al-Assad regime victory or a protracted civil war. It undoubtedly views the fight for the survival of the regime as a way to both maintain influence and further its regional goals through Syria's proximity to Israel.

The Palestinians are also potential beneficiaries. Instability created by the conflict brings uncertainty for Israel and Jordan, along with opportunities for Palestinians in the West Bank, Gaza, and refugee camps along the Syrian coast and in Jordan. They could either join the jihad against the Alawites or benefit peripherally from political arrangements brokered by the United Nations, the Arab League, or others.

Finally, the Kurds in northern Syria may benefit by either supporting the regime or negotiating with the Turks and allying with their Kurdish brethren in northern Iraq. Although the latter strategy is unlikely because of divisions in Iraq, it should not be completely discounted. The Kurds have proven to be masters at playing all sides simultaneously, out of necessity.

Who loses as the conflict drags on? U.S. allies Jordan and Israel, along with the broader social fabric of Syria and Lebanon, stand to lose the most. Refugees, economic hardship, and cross-border tensions are likely to stir political sentiment and embolden Palestinian and other political groups in Jordan to press for radical change. Such political unrest opens the door for al Qaeda and its affiliates to strike at both the Jordanian monarchy and Israel. Israel, distracted by the conflict in Syria and Iran's nuclear ambitions, may have to confront a much more permissive Egypt and aggressive Palestinian population in Gaza and the West Bank.

More broadly, Iraq stands to lose from the spillover of sectarian strife within its own borders. An extension of the conflict would only add to Iraq's unification challenges. And the governments of Saudi Arabia, Kuwait, the United Arab Emirates and Qatar will need to monitor stirrings of rebellion among their Shia populations, which Bahrain has already experienced. Efforts by these majority-Sunni regimes to fuel the fight against the Alawites in Syria could ricochet back in the form of internal political and social unrest. Their financial assistance could also find its way to al Qaeda affiliates.

With no apparent coalition of interested parties to broker peace or guarantee a decisive victory, the civil war will likely continue without some form of Western political and military intervention. Although outside efforts to arm the rebels would help level the playing field in Syria, such a strategy would not ensure victory, and the weapons could fall into the hands of extremists for use against Israel, Jordan and other neighboring countries. The regime's retaliation with chemical weapons against more heavily armed rebels could spur outside military intervention on humanitarian grounds.

The fast pace of change in Syria is another game-changing variable to consider. What could be done today might not be possible tomorrow. Inaction has its price: continued loss of innocent life, the hardening of positions on both sides of the conflict (which makes negotiating a settlement more difficult), and a vacuum filled by extremists are just a few examples of the risks that inaction poses.