Alawaism is a combination of Christian and Islamic traditions into a separate Religion (For example they celebrate the Christian Holidays of Christmas, Epiphany and Easter and use wine in their Religious Services but then calls themselves Muslims). Now Sunni Muslims do NOT consider the the Alawite or Druse to be Moslems) but both believe in the Five Pillars of Islam (and the Alawite and Druse were influenced by Ismaili Islamic influence).
For more on the Alawite see:
http://countrystudies.us/syria/32.htmWhile Ismaili is a branch of Shiite Islam, Ismaili is of the "Seveners" branch of Shiite NOT the "Twelvers" branch that dominates Iran. The Difference is over the Successor to the fourth Caliph Ali (Mohammad's son-in-law). All Moslems recognize the first four Caliphs, but start to split at the death of Ali (Through a small branch broke during Ali's Caliphate forming a third branch of Islam, independent of both Sunni and Shiite Traditions). The Shiite's refused to accept the fifth Caliph as legitimate and instead choose Ali's son as their and thus the fifth "Imam" of the Shiites. The Seveners split from the Twelvers at the death of the Ali's Grandson (or the Seventh Imam if you count the first four Caliphs as the first four Shiite Imams). The Majority of Shiites continue to follow Ali's blood line till the 12th Imam disappears as a child during a palace coup. With the disappearance of the twelfth Imam, the Shiite adopted a position similar to the Seveners, i.e. waiting for their leader to come back at the end of time (Though as Moslems they accept that Christ will come back at that time, the Shiites just believe before Christ comes back the Mahdi will lead the Moslem to unity and Victory over the enemies of God). Yes, my fellow Christians the Moslems also believe it is Christ that will come back to earth at the end times NOT Mohammad.
The difference is important for the Seveners and the Twelvers BOTH believe is two DIFFERENT people who will come back and lead them to Victory and Both view each other as Heretics (and both are called heretics by the Sunnis). Thus while Syria is Baathist, its President is NOT of the same branch of Islam as Iran. The Traditional allies of the Alawite in the Middle east had been the Christians of Lebanon (Which is why the father of the present President of Syria sent in the Syrian Army, to save the Christians who were losing the Lebanese Civil War to the Moslems). In the case of Sadr, he is looking for Allies for the upcoming war between America and Iran. I suspect he is a Middle man for Iran, but that the US left him go to Syria trying to keep his Militia happy. The US can NOT fight the Sunni outside Baghdad AND fight Sadr's Militia, thus the US wants to keep him happy and under the control of the Ayatollahs of Iraq.
One of the differences between Sunni and Shiite Islam, is that the Shiite have traditionally been outside the Government while the Sunni were the Government in most Moslems Countries. Do to this fact, Shiite's tend to look to their Religious leaders more than their Political Leaders. Another difference is that the Shiite Religious structure is very Rigid, to better withstand Political efforts to control the Religious hierarchy. In the Sunni Religion the Government PICKS THE RELIGIOUS LEADERS and as such all official Sunni Religious Leaders are Political puppets of the Government. In the Shiite religion the religious hierarchy wants to control the Government while keeping their own Independence (Thus the Iranian solution of having two national leaders, its "Supreme Leader" who is the top religious leader in Iran, and a President of the Islamic Republic).
My point here, Syria is NOT Shiite but Syria's leadership is also NOT Sunni, but when you need allies you take what you can get.
For more on the Ismaili:
http://www.globalsecurity.org/military/intro/islam-ismaili.htmFor more on the Twelves:
http://www.globalsecurity.org/military/intro/islam-ithna-ashari.htmFor more on the various branches of Islam:
http://religion-cults.com/Islam/islam5.htmlSome Information on the Ismali Offshoot the Assassins (Very Strong Influence at the time of the Crusades):
http://www.accampbell.uklinux.net/assassins/assassins-html/index.htmlFor more on Syria see:
http://countrystudies.us/syria/Some of the Difference between Shiite and Sunni Moslems:
http://glimpseofiraq.blogspot.com/2005/02/sunni-shiite-iraq.html