Nationalism is a key weapon that the ruling class uses against the working class in order to keep us divided and fighting each other in the interests of those parasites who rule us. Nationalism is used to create the illusion that there can be all-class unity between local bosses and workers.  This unity is a death sentence for our class. A major tragedy in Syria is the way that nationalism, in the form of religion, is being used to divide the working class and get workers to kill themselves in the interests of the imperialists. The major imperialists are in a proxy conflict: Russia and China, with Iran, against the U.S., U.K., France, Saudi Arabia and Qatar for control of Syria.
The old Communist Movement did not have confidence that the working class would fight directly for communism. It believed that nationalism could be a progressive element in the fight against the capitalist class.  Every national liberation movement and alliance with religious organizations has been doomed to be chained to capitalism and has never led, nor will lead, to communism. 
The Progressive Labor Party does not agree with nationalism, nor will we align with “lesser-evil” national  bosses.  Though Russia is on a roll right now by supplying weapons systems to Syria with impunity, it is still a repressive fascist state with designs on dominating the world’s resources like any imperialist.  A victory for Syria’s president Assad is still a defeat for the working class.
A victory for the rebels would also be a defeat for workers.  The rebels are aligned on two ideological foundations — one is a secular liberal nationalism and the other is an autocratic Islamism that is concretely tied to Al Qaeda.  The recent “victory” of U.S. imperialism in Libya has shown what misery is in store for the working class as thousands of armed militia and the thugs in government in Benghazi both terrorize our class.
This future is a probability for the working class of Syria should the rebels come out victors in that civil war.  The resolution of a rebel victory would most likely be a second civil war between the Islamists and the nationalist Free Syrian Army.  The nationalists are already losing ground to the better-trained and tenacious Islamists.
The recent victories by Syria and its Hezbollah allies have intensified the contradiction between different sects of Islam.  In a part of the world where Druze, Christian, Alawite, et al, have lived together fairly peacefully, the regional Hegemons of Qatar and Saudi Arabia, most likely acting as a front for the U.S. and its puppet arch-imperialist Obama, are frantically inciting animosity between the sects. They are arming the rebels with weapons that can be used against working-class civilians. Religion, the bosses’ ideological weapon, is now being used to divide the working class and cause potential civil wars in Jordan and Lebanon and is also a factor in the unrest in Turkey. 
The U.S. is desperate to force Russia out of the Middle East and Russia is just as tenaciously guarding its port in Tartus, Syria.  Russia has countered the U.S. build-up of Patriot missiles, fighter jets, and troops in Jordan by sending aircraft carriers, submarines, and other weapons to its base in Syria.  Iran has contributed Hezbollah guerillas and military planning.  Assad is now in the process of mopping up the rebels in Aleppo and, most likely, once they have severed their supply lines, will then smash them piecemeal in the countryside.
This military disaster for the U.S. proxy forces in Syria is just another blemish on the ineffectual leadership of Obama. It’s part of the Vietnam Syndrome (the rulers’ fear of mass GI rebellions) that still haunts the U.S. bosses and inhibits them from entering wars that they need to preserve their empire. But the  Vietnam Syndrome will not be enough to keep the U.S. from other wars of aggression against the world’s working class. That aggression will only cease when the U.S. and all of the world’s capitalists are destroyed by a communist revolution led by the PLP.