More than 1,500 people have been killed since Syrian government troops backed by Russia launched a ferocious attack on eastern Ghouta on February 18. Airstrikes have reduced much of the area near Damascus to ruins. According to the UN, there were an estimated 400,000 people trapped inside the besieged enclave without access to food and water when the offensive began.

The town of Douma, with its 200,000 residents, is now the only remaining Ghouta pocket still under rebel control. The full recapture of eastern Ghouta would mark a significant victory for Syrian President Bashar Assad. Referring to the month-long assault on the enclave, UN Secretary General Antonio Guterres demanded "this hell on earth" be stopped immediately.

According to activists and doctors in the region, several people have suffered symptoms consistent with those triggered by a chlorine gas attack and had to be treated in hospital. French President Emmanuel Macron has warned the Syrian regime that the use of chemical weapons will result in French retaliation, but the Syrian government claims it has never used this kind of munition.

A man and child look at the remains of a missile in Douma, the largest in eastern Ghouta. More than 300,000 people have been killed since the conflict began in 2011, when the government cracked down on protesters who were calling for the release of political prisoners and for President Assad to step down.

Activists say people in Douma have little food or water. Marten Mylius, the emergency relief coordinator for CARE in the Middle East, told DW that "after the tunnels were destroyed and the crossings closed, the price of basic foods skyrocketed. One kilo of rice now costs $4.50 (€3.66). A lot of people cannot afford that anymore. In other words, we are witnessing a rapid spread of malnutrition."

Aid access to eastern Ghouta is difficult because there is no direct route from neighboring countries. "In Idlib, for example...you can get in directly from the Turkish border. You can wait with supplies at the border and then bring in the convoy. It is much more difficult in eastern Ghouta," Mylius told DW.

Syria has been engulfed in a devastating civil war since 2011 after Syrian President Bashar Assad lost control over large parts of the country to multiple revolutionary groups. The conflict has since drawn in foreign powers and brought misery and death to Syrians.

Syria's army, officially known as the Syrian Arab Army (SAA), is loyal to Syrian President Bashar al-Assad and is fighting to restore the president's rule over the entire country. The SAA has been fighting alongside a number of pro-Assad militias such as the National Defense Force and has cooperated with military advisors from Russia and Iran, which back Assad.

Turkey, which is also part of the US-led coalition against IS, has actively supported rebels opposed to Assad. It has a tense relationship with its American allies over US cooperation with Kurdish fighters, who Ankara says are linked to the Kurdistan Workers' Party (PKK) fighting in Turkey. Turkey has launched multiple military offensives targeting Kurdish militias.

The Kremlin has proven to be a powerful friend to Assad. Russian air power and ground troops officially joined the fight in September 2015 after years of supplying the Syrian army. Moscow has come under fire from the international community for the high number of civilian casualties during its airstrikes. However, Russia's intervention turned the tide in war in favor of Assad.

A US-led coalition of more than 50 countries, including Germany, began targeting IS and other terrorist targets with airstrikes in late 2014. The anti-IS coalition has dealt major setbacks to the militant group. The US has more than a thousand special forces in the country backing the Syrian Democratic Forces.

The Free Syrian Army grew out of protests against the Assad regime that eventually turned violent. Along with other non-jihadist rebel groups, it seeks the ouster of President Assad and democratic elections. After suffering a number of defeats, many of its members defected to hardline militant groups. It garnered some support from the US and Turkey, but its strength has been greatly diminished.

Fighting between Syrian Kurds and Islamists has become its own conflict. The US-led coalition against the "Islamic State" has backed the Syrian Democratic Forces, an alliance of Kurdish and Arab militias. The Kurdish YPG militia is the main component of the SDF. The Kurds have had a tacit understanding with Assad.

"Islamic State" (IS) took advantage of regional chaos to capture vast swathes of territory in Iraq and Syria in 2014. Seeking to establish its own "caliphate," IS has become infamous for its fundamentalist brand of Islam and its mass atrocities. IS is on the brink of defeat after the US and Russia led separate military campaigns against the militant group.

IS is not the only terrorist group that has ravaged Syria. A number of jihadist militant groups are fighting in the conflict, warring against various rebel factions and the Assad regime. One of the main jihadist factions is Hay'at Tahrir al-Sham, which controls most of Idlib province and has ties with al-Qaeda.

Iran has supported Syria, its only Arab ally, for decades. Eager to maintain its ally, Tehran has provided Damascus with strategic assistance, military training and ground troops when the conflict emerged in 2011. The Iran-backed Lebanese Shiite militant group Hezbollah also supports the Assad regime, fighting alongside Iranian forces and paramilitary groups in the country.