The latest offensive by Syria's oppositional forces against President Bashar Assad's army and the Kurdish population in northeastern Syria, has ended four years of relatively static conflict in Syria's civil war. 

What has happened so far?  

On Wednesday, Hayat Tahrir al-Sham, or HTS, an Islamist militia, launched a surprise offensive against the government forces of President Bashar Assad.    

On Friday, pro-Turkish rebels under the lead of HTS managed to seize Aleppo, Syria's second largest city, as well as scores of surrounding villages.  

According to reports, their next attempt will be to take the city of Hama.  

Nanar Hawach, senior Syria analyst at the International Crisis Group, an independent organization working to prevent wars, told DW that "on Sunday, heavy government reinforcement arrived at Hama and they started pushing HTS north, recapturing some towns and villages."   

Hawach assumes a major counter-offensive is imminent, with the next phase of a "high intensity Syrian civil war all over again the next couple of weeks and months."

Hama has seen the trajectory of the civil war shift before, back in 2015. 

After Syria's population had started pushing for democratic change in 2011, rebel groups were initially successful in their battle against government forces.  

Yet, in 2015, Assad's troops were able to stop the offensive in Hama when Assad's allies Russia and Iran stepped up their military support.

In the following years, countless airstrikes on Assad's opponents have helped the regime's troops recapture most of the territory it had originally lost. 

Who is fighting in Syria? 

The driving force behind the current offensive is the pro-Turkish HTS.

The group was labeleda foreign terrorist organization by the US in 2018, and was previously affiliated with al-Qaida, another US-designated terror outfit. 

HTS controls Syria's northeast region of Idlib, which has become the country's last opposition stronghold.

Idlib is home to around 4 million internally displaced Syrian refugees, according to the United Nations.  

Apparently, however, HTS-led groups are not solely trying to regain control of areas held by President Assad's forces.  

Turkish-backed factions from the opposition Syrian National Army, or SNA, have launched a parallel operation, named "Dawn of Freedom," targeting majority Kurds in the country's northeast.  

Turkey, which borders Syria to the north and largely remains in opposition to the government in Damascus, has regularly attacked the Kurdish autonomous region and targeted groups Ankara has labeled "terrorist," like the Syrian Democratic Forces, or SDF. 

Who supports Syria's Bashar Assad, and why?  

For Moscow, supporting Assad promises several advantages, despite Russia's ongoing war to Ukraine.

The alliance with Syria strengthens Russia's strategic influence in the region and provides training opportunities for Russia's military and mercenaries ahead of their deployment in Ukraine. 

Kremlin spokesman Dmitry Peskov said at a recent press conference that Russia will "of course continue to support Bashar Assad," adding that Russia would draw up a "position on what is necessary to stabilize the situation." 

Supporting Assad is also likely to have made it easier to close ranks with Iran, which has become an important ally for Russia.  

The Assad regime is also an important partner in Iran's so-called "Axis of Resistence" — a collection of countries and militias who see America and Israel as their main enemies. Other "axis" partners include Hezbollah in Lebanon and Yemen's Houthi rebels. 

Like Russian President Vladimir Putin, Iran's President Masoud Pezeshkian has also assured Assad that he will provide all the support needed to put down this latest uprising. 

Furthermore, on Monday, the London-based opposition group Syrian Observatory for Human Rights reported that around 200 Iraqi fighters under Iranian command had entered Syria in pickup trucks to support an army counter-offensive near Aleppo. 

Why are they fighting now? 

"It is no coincidence that the pro-Turkish Jihadist insurgents in Syria started the offensive right after the ceasefire implementation between Israel and Hezbollah," Lorenzo Trombetta, a Middle East analyst and UN consultant, told DW. 

Hezbollah — designated as a terrorist organization by several countries, including the US and Germany — is financed, equipped and trained by Iran. But it has been considerably weakened by a year of fighting with Israel at the Lebanese border.  

"Furthermore, this pro-Turkish offensive resulted in a weakening of the Iranian and pro-Iranian front all over the Middle East," Trombetta added. 

Iran's defenses have been weakened in its recent tit-for-tat with Israel.  

Israel has also increased attacks on Iranian bases inside Syria and has cut supply routes between Lebanon and Syria.   

And Syria's other key ally, Russia, has been occupied with its war against Ukraine for nearly three years.  

While it is impossible to predict how the current situation in Syria will unfold, Crisis Group's Nanar Hawach says one thing seems inevitable.

"Unfortunately, civilians will bear the brunt of these clashes," he told DW.

Edited by: Jon Shelton