A group of state and national lawmakers with the German anti-immigration AfD kicked off a week-long trip to Syria by meeting with allies of Syrian President Bashar al-Assad on March 6. Their goal? To prove Syria is safe enough to repatriate refugees living in Germany. Berlin sharply criticized the move, with a government spokesman saying: "Whoever courts this regime disqualifies themselves."

The Republican senator made two controversial, private trips to Syria. The first was in May 2013 when he met with members of the opposition Free Syrian Army. Shortly thereafter, the US began training and equipping opposition forces. The second was in January 2017, when McCain met with troops in Kurdish-held northern Syria. Although criticized in the media, Washington hasn't censured the senator.

In January 2017, the Democratic congresswoman from Hawaii and military veteran went on a "fact finding" visit to Syria. In a complete reversal with US policy, Gabbard met with Assad during her trip. She was staunchly criticized by both Republicans and Democrats for the visit. Gabbard is one of the few US politicians to voice doubt over whether the Assad regime has been using chemical weapons.

Three members of the European Parliament led by Spanish MEP Javier Couso Permuy visited Syria and met with Assad as part of a "working visit." The EU parliament denied that the body paid for the trip, calling it an unofficial visit. The MEPs later formed a group called the Syria Peace Process Support Group, which met Assad in Syria again in March 2017.

Pedro Agramunt, the former president of the Parliamentary Assembly of the Council of Europe (PACE) went on a Russia-sponsored trip to Syria in March 2017. During the visit, the Spanish senator not only met with Assad, but with Russian officials, as well. Although he apologized, PACE prohibited him from traveling or speaking on behalf of the assembly. PACE did not have the power to dismiss him.

In February 2015, four French MPs from different political parties met with Assad — bucking France's no-contact policy with the regime — and toured areas hit hard by the war, including the city of Homs (pictured above).Their trip was swiftly condemned by the French government and there were calls for the MPs to resign. All of them ended up staying in their posts.

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.