To be sure, there are stark differences between Iraq then and Syria now. There has been no foreign invasion or occupation, and there are lots of specific differences between the two countries. While Iraq under Saddam had a Sunni-dominated Baathist government and a Shiite majority, in Syria the Alawite sect of Bashar al-Assad is dominant politically and Sunnis are dominant numerically.
A further wrinkle is the presence of the descendants of Palestinians who lost their homes in the foundation of Israel, and now number more than 400,000 people.
The Palestinian community in Syria appears split. While many have taken up arms against Assad, still others have fought on his behalf. There have been persistent claims of Palestinian militiamen from Popular Front for the Liberation of Palestine - General Command fighting on the side of Assad's forces in some districts of the capital.
The AP reports there's an element of inter-Palestinian conflict in the fighting, with the PFLP-GC saying the fighting started after Palestinians fighting with the rebellion attacked civilians in the Palestinian refugee camp of Yarmouk.
But there are plenty of similarities, particularly the substantial presence of jihadis in Syria, much as they were in Iraq. These are very much the same sort of people who were fighting the US troops in Iraq (and running death squads against Shiites) during the war there. Aaron Zelin shares on Twitter this pre-martyrdom picture of Libyan Ahmad Bishasha, characteristic of Al Qaeda-style propaganda. Jahbat al-Nusra claims that Mr. Bishasha carried out a suicide attack on that group's behalf yesterday.