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.

Since 1999, the UN has been trying to pacify the eastern region of the DR Congo. The mission known as MONUSCO has nearly 20,000 soldiers and an annual budget of $1.4 billion (1.3 billion euros). Despite being the largest and most expensive mission of the United Nations, violence in the country continues.

UNAMID is a joint mission of the African Union and the UN in Sudan's volatile Darfur region. Observers consider the mission a failure. "The UN Security Council should work harder at finding political solutions, rather than spending money for the military's long-term deployment," says security expert Thierry Vircoulon.

Since the beginning of South Sudan's civil war in 2013, nearly 4 million people have been displaced according to the UN. Some of them are being sheltered in UN compounds. But when clashes between government forces and rebels broke out in the capital Juba in July 2016, the blue helmets failed to effectively intervene. Later, the Kenyan UNMISS commander was sacked by former UN chief Ban Ki-moon.

UN peacekeepers in Mali are monitoring compliance with the peace agreement between the government and an alliance of Tuareg-led rebels. But Islamist terrorist groups such as AQIM continue to carry out attacks making MINUSMA one of the UN's most dangerous military intervention in the world. Germany has deployed more than 700 soldiers as well as helicopters.

MINUSCA, the UN's mission in Central Africa Republic has not helped to improve the image of the United Nations in Africa. French troops have been accused of sexually abusing children by the Code Blue Campaign. Three years on, victims haven't got any help from the UN. Since 2014, 10,000 soldiers and 1,800 police officers have been deployed. Violence in the country has receded but tensions remain.

The UN mission in the Westsahara known as MINURSO has been active since 1991. MINURSO is there to monitor the armistice between Morocco and the rebels of the "Frente Polisario" who are fighting for the independence of the Western Sahara. In 2016, Morocco which has occupied this territory since 1976, dismissed 84 MINURSO staff after being angered by a statement from the UN Secretary-General.

The UN mission in Ivory Coast fulfilled its objectives on June 30, 2016 after 14 years. Since 2016, the troops have been gradually withdrawn. Former Secretary-General Ban Ki-moon said this was a "turning point for the United Nations and the Ivory Coast." But only after the full withdrawal will it be clearly known whether or not the mission was successful on a long-term basis.

The UN deployment in Liberia is - as in neighboring Ivory Coast - will soon be history. The soldiers are leaving by mid-2017. Since the end of the 14-year civil war, UNMIL has ensured stability in Liberia and helped build a functioning state. Liberia's government now wants to provide security for itself. The country is still struggling with the consequences of a devastating Ebola epidemic.

The UNISFA soldiers are patrolling the disputed oil-rich region of Abyei. Sudan and South Sudan both claim to be rightful owners of this territory located between the two countries. More than 4,000 blue helmets from Ethiopia are deployed. Ethiopia is the world's second largest peace-keeping contributor. At the same time, the Ethiopian army is accused of human rights violations back home.

UN peacekeepers in Somalia are fighting under the leadership of the African Union in a mission known as AMISOM. The soldiers are in the Horn of African country to battle the al-Shabaab Islamists and bring stability to the war-torn nation. Ethiopia, Burundi, Djibouti, Kenya and Uganda, Sierra Leone, Ghana and Nigeria have all contributed their troops for AMISOM.