The Syrian Civil War began in March of 2011 as part of the Arab Spring uprisings. Calls for the removal of President Bashar al-Assad were violently suppressed by the government (Syrian Arab Republic). The backlash spawned the Free Syrian Army.
Kofi Anan of the UN brokered a cease fire in April of 2012. The cease fire officially lasted until the 1st of June but both sides of the conflict were violating the agreement in May. Islamic radicals joined the fray. Druze and Hebollah militias from southern Lebanon (backed by Iran) began fighting on the side of the Assad government. Salafist jihadists (Sunnis) and the Syrian Democratic Front (Kurdish and Syrian) joined on the side of the FSA.
The US began training members of the FSA in 2012. Israel has carried out airstrikes against Hezbollah forces in Syria. The Russian Federation has a navy base in Syria and has assisted Assad with weapons and training.
In 2014 it appeared the FSA was gaining the upper hand in the conflict. Suddenly, out of nowhere, and for absolutely no apparent reason, ISIS showed up. Maybe Allah led them to Syria. They joined the conflict as a third belligerent, allied to neither Assad nor the FSA. ISIS managed to rescue Assad by confounding the FSA. Allah retained “plausible deniability” in his assistance of Putin‘s interests.
The US sent troops to intervene in 2015 as did the Russians in 2016. Turkish forces replaced the US forces but attacked the Kurds as well as ISIS forces in 2019. The current situation in the conflict is a stalemate.