The Syrian civil war, which has devastated the entire country of Syria and its neighbors, is a complex conflict that involves several nations, rebel groups and terrorist organizations.

What started as a nonviolent protest in 2011 quickly escalated into full-blown warfare. Since the fighting began, more than 470,000 people have been killed, with over 1 million injured and millions more forced to flee their homes and live as refugees.

Although many complicated motives led to the Syrian civil war, one event, known as the Arab Spring, stands out as perhaps the most significant trigger for the conflict.

In early 2011, a series of political and economic protests in Egypt and Tunisia broke out. These successful revolts, dubbed the Arab Spring, served as an inspiration for pro-democracy activists in Syria.

However, in March of that year, 15 Syrian schoolchildren were arrested and tortured for writing graffiti that was inspired by the Arab Spring. One of the boys was killed.

The arrests sparked outrage and demonstrations throughout Syria. Citizens demanded the release of the remaining children, along with greater freedoms for all people in the country.

But the government, headed by President Bashar al-Assad, responded by killing and arresting hundreds of protestors. Shock and anger began to spread throughout Syria, and many demanded that Assad resign. When he refused, war broke out between his supporters and his opponents.

“The Syrian government must stop shooting demonstrators and allow peaceful protests; release political prisoners and stop unjust arrests; allow human rights monitors to have access to cities like Dara’a; and start a serious dialogue to advance a democratic transition,” U.S. President Barack Obama stated in a 2011 speech.

“Otherwise, President Assad and his regime will continue to be challenged from within and isolated abroad,” Obama said. By July 2011, Syrian rebels formed the Free Syrian Army (FSA), and a civil war was imminent.

Assad’s crackdown is just one of several problems plaguing Syria.

Even before the Arab Spring-inspired incident, many Syrian citizens were dissatisfied over the government’s incompetency, the people’s lack of freedoms and the general living conditions in their country.

Assad became president in 2000 after the death of his father. Several human rights groups have accused the leader of habitually torturing and killing political opponents throughout his presidency.

A lagging economy, high unemployment, government corruption and a severe drought were other issues that generated frustration among people under Assad’s rule.

Another problem was a tense religious atmosphere in the country: Most Syrians are Sunni Muslims, yet Syria’s government is dominated by members of the Shia Alawite sect. Tensions between the two groups is an ongoing problem throughout Syria and other nations in the Middle East.

Since the start of the war, the situation in Syria became much more complicated, as other countries and organized fighters have entered the picture.

Essentially, the Syrian government’s main backers are Russia, Iran and Hezbollah (a militia group based in Lebanon). The United States, Saudi Arabia, Qatar, Turkey and other western countries are described as supporters of moderate rebel groups. Many newer rebel groups have emerged since the war began.

The ongoing conflict also encouraged terrorist organizations, such as ISIS and al-Qaeda, to join in on the chaos. These groups are primarily made up of Sunni militants.

The rebels and Assad’s forces have both fought separate battles against ISIS, while also waging war against each other. To further complicate the dynamics, the United States has also led an international bombing campaign against ISIS targets since 2014.

In April of 2017 and 2018, the United States launched military attacks against chemical weapons sites in Syria. Assad’s office spoke out against the 2017 attacks and said in a statement, “What America did is nothing but foolish and irresponsible behavior, which only reveals its short-sightedness and political and military blindness to reality.”

After the 2018 attack, U.S. President Donald Trump told the press: "The purpose of our actions tonight is to establish a strong deterrent against the production, spread and use of chemical weapons. Establishing this deterrent is a vital national security interest of the United States. The combined American, British and French response to these atrocities will integrate all instruments of our national power—military, economic, and diplomatic.”

Experts estimate that 13.1 million Syrians need humanitarian assistance, such as medicine or food. Nearly 3 million of these people live in hard-to-reach areas.

More than 5.6 million refugees have fled the country, and another 6.1 million are displaced within Syria. Turkey, Lebanon and Jordan are credited with hosting the most Syrian refugees.

By September 2018, Assad's forces had reclaimed control of most of the country’s biggest cities, although parts of the country were still held by rebel and jihadist groups and the Kurdish-led SDF alliance. The last remaining rebel stronghold was the north-western province of Idlib. ISIS’s presence in Syria, meanwhile, has been greatly diminished.

Since 2014, the United Nations has hosted nine rounds of mediated peace talks, known as the Geneva II process. Despite this intervention, little progress has been made.

After negotiations failed in 2014, UN mediator Lakhdar Brahimi apologized to the Syrian people in a statement, saying, "Unfortunately, the government has refused, which raises the suspicion of the opposition that, in fact, the government doesn't want to discuss the (transitional governing body) at all," he said.

Both the Syrian government and rebels appear unwilling to agree on terms of peace. If nothing changes, this war-torn area of the world is likely to be the site of more violence and instability.