Russia and Syria counter claims of responsibility for "gas attack"
Moscow and Damascus blamed rebel stockpiles of chemical weapons for the tragedy that has cost scores of civilians lives. Turkey said autopsies revealed the victims were likely subjected to the illegal nerve agent sarin.
World powers engaged in a series of blame trading and increasingly volatile rhetoric on Thursday in the aftermath of a suspected gas attack in the Syrian town of Khan Sheikhoun.
One day after Russia vetoed a United Nations resolution put forward by the UK, US and France to blame Damascus for the attack, Moscow backed a claim by the government of Syrian President Bashar al-Assad that the catastrophe was the result of an airstrike against a rebel warehouse that happened to be storing chemical weapons.
The Kremlin issued a statement saying that Russian President Vladimir Putin found it "unacceptable to make groundless accusations against anyone without conducting a detailed and unbiased investigation."
In response, Turkey's President Recep Tayyip Erdogan said it had "saddened us that this has not been understood," by Moscow, and that the Kremlin continued to ask "is Assad behind this or not?" even after it had become clear that Damascus was to blame.
According to activists, at least 86 people were killed due to the release of a chemical nerve agent, and hundreds more needed medical attention for respiratory problems and other severe injuries. The attack occurred in Idlib province, an area on the Turkish border mostly controlled by al-Qaeda affiliated rebels.
Turkey suspects sarin use
Despite initial confusion over the exact nature of the substance, the Turkish Health Ministry said on Thursday that it had conducted autopsies on several victims and could confirm that they had been subjected to chemical weapons, most likely the internationally outlawed sarin gas. Read: Syria's chemical weapons, explained
The French government immediately called for Assad regime to be prosecuted over the incident.
"These crimes must not remain unpunished…one day, international justice will rule on Assad," said French Foreign Minister Jean-Marc Ayrault in an interview with CNews television. German Chancellor Angela Merkel added that it was a "scandal" that the UN resolution had failed.
War with no end
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.
The northern watchman
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. The Turkish military has intervened alongside rebels in northern Aleppo, Afrin and Idlib province.
The eastern guardian
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.
The western allies
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.
The new jihadists
"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 facing defeat in both countries after the US and Russia led separate military campaigns against the militant group.
The old jihadists
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.
The Persian shadow
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.
Syria: International inquiry only under our conditions
Damascus has said it is open to the idea of an international investigation, but only on very strict terms. Top diplomat Walid al-Moualem said Syria had been subjected to biased inquiries by the global community in the past, and would not allow that to happen again.
"It must not be politicised, it must leave from Damascus and not Turkey. We have numerous questions about this subject. When we are certain these questions are addressed with convincing answers, we will give you our response," he said.
Moualem also reiterated the claim, echoed by Moscow, that the tragedy occurred because the rebels had been stockpiling sarin gas, and the Syrian army had no way of knowing it was there.
"I confirm to you once again that the Syrian Arab Army has not and will not use this type of weapon against our people and our children, and not even against the terrorists who kill our people," the foreign minister said.
US looks at military intervention
After marking a monumental shift in six years of US policy calling for Assad to step down, in recent weeks top US officials such as Secretary of State Rex Tillerson and UN envoy Nikki Haley have said it was no longer a major priority.
Events in Khan Sheikhoun.appeared to have changed matters, however. Tillerson said on Thursday that "there is no doubt in our minds, and the information we have supports that Syria, the Syria regime under the leadership of President Bashar al-Assad are responsible for this attack."
He cautioned Moscow to "consider carefully their continued support for the Assad regime."
President Donald Trump said that Assad had commited an "affront to humanity" and that "the message from the United States must be that this will not stand."
An official from the Defense Department told reporters that the Pentagon was preparing plans for a range of possible military options the United States might take in response to the attack.