One reason the Assad family, which has been running Syria since the 1960s, has so few friends is because for decades the Assads were Shia Moslems running a country that was mostly Sunni. In order to make that work the Assads needed powerful friends and in the 1980s they hooked by with Shia Iran. This was offensive to the majority of Arabs who are Sunni because the Syrian Shia are Arab and here they were, led by this Assad family, betraying their fellow Arabs. The Assads were even more hated because they would play off Sunnis against Sunnis when it suited them. Examples of this could be seen when the Assads allowed PKK (Turkish Kurdish separatists) terrorists to travel through Syria from bases in northern Iraq to targets inside Turkey. The Turks (Sunnis) eventually figured this out and demanded that the Assads stop. At one point this involved several divisions of Turkish troops assembling at the Syrian border. This got the Assads to agree to drop the PKK sanctuary but as the Turks learned, the Assad reputation for lying and betrayal was well deserved and Syrian support for the PKK never completely disappeared. All this in order to keep Syrian Kurdish separatists quiet, or at least unable to depend on support from PKK.
Despite the Assads being Shia, after the 2003 American invasion of Iraq the Assads allowed Sunni Islamic terrorists to fly into Syria and move freely into Iraq. The Assads had long provided sanctuary for Sunni Islamic terrorists, even though many of these Sunni terrorists killed Shia at every opportunity. In return for sanctuary in Syria the Islamic terrorists had to behave while inside Syria and help Syrian police track down and kill any Sunni Islamic terrorists would could not control their Shia bloodlust.
Inside Iraq it was a different matter. Although the Sunni Islamic terrorists coming in via Syria were expected to mainly go after Americans (the main enemy of Iran) in Iraq these Sunni Islamic terrorists also killed lots of Iraqi Shia. This caused a lot of factional friction inside Iran but Iran never told the Assads to keep the Sunni Islamic terrorists out of Iraq.
Iran was officially against support for Sunni Islamic terrorists but was so eager to kill Americans that they were willing to let 20 Iraqi Shia get murdered for each American soldier killed in Iraq. The Iraqi dead were, after all, only Arabs and not ethnic Iranians. It’s that sort of thinking that has enraged the Arab world since 2003 and created an increasingly brutal conflict between the Iran led Shia and the Saudi led Sunnis inside Syria. Meanwhile the Americans tried their own solution after 2003 and collected compelling evidence of the Syrian Islamic terrorist connection and presented it to the Syrian leadership. The Assads said they would shut down the terrorist pipeline but never really did so. Throughout all this the Assads managed to screw (and enrage) just about everyone, except Iran.
When the Arab Spring uprisings began in 2011 Syria was a shaky dictatorship where the Shia minority was propped up by largely Shia Iran and barely hanging on. Next door there was one potential ally; the powerful Shia militia (Hezbollah) in Lebanon that Iran had helped create in the midst of the Lebanese Civil War (1975-90). The only reason the Assads survived 2011 was because of the support of Iran and Hezbollah.
The Sunni Arabs always found the Shia (Assad) dictatorship in Syria offensive. But the founder (in the 1960s) of that dynasty (Hafez Assad) took advantage of factionalism among the Sunni majority (75 percent of all Syrians) and formed a ruling coalition that got a boost in the 1980s (when the Iran-Iraq War was raging) when the Assads, who had many political disputes with Saddam Hussein, decided to become a client-state of Iran. That has ended up as a bloody Syrian civil war that is currently deadlocked. This is mainly because Iran and the Arab Gulf states do not want to fight each other directly, at least not yet. In the meantime these proxy wars will do and the West (especially the voters) is not interested enough to get involved. Naturally both Shia and Sunni accuse the West of causing the problem, but that’s another matter entirely.