On 4 April 2017, it was reported that the Syrian town of Khan Shaykhun – controlled at the time by the Tahrir Al-Sham Alliance – had been the object of an airstrike by the air force of the Government of President Bashar Al Assad. As a result of the airstrike, chemical agents poisoned large numbers of civilians.
In a report released on 30 June 2017, the Fact-Finding Mission of the Organization for the Prohibition of Chemical Weapons (OPCW) estimated the number of deaths “as approximately 100 people” and determined that “Sarin or a Sarin-like substance” had been used as a weapon in Khan Shaykhun. It took until 27 October 2017 for the OPCW-United Nations Joint Investigative Mechanism to take position on the responsibility for the attack and affirm that the Leading Panel of the mechanism itself was “confident that the Syrian Arab Republic is responsible for the release of Sarin at Khan Shaykhun on 4 April 2017”.
In the aftermath of the attack, however, several countries condemned the action and the United States (US), the United Kingdom and France openly called into question the responsibility of the Syrian Government. The US President, Mr. Donald Trump, condemned the attack as “intolerable” and openly blamed the inaction of his predecessor Barack Obama, who, after establishing “a ‘red line’ against the use of chemical weapons did nothing”. On its part, the Syrian government denied any involvement in the use of chemical weapons. The Government of the Russian Federation offered alternative explanations of the events, mentioning the fact that the Syrian Air Force could have “bombed an underground factory producing chemical warfare agents” or alluding to a possible “provocation by the terrorists”. Within the United Nations (UN) Security Council, a draft resolution condemning the attack – tabled by France, the United Kingdom and the US – was vetoed by the Russian Federation, with the abstention of China, Ethiopia and Kazakhstan.
Two days after the event, the US launched a Tomahawk missile attack from two destroyers in the Mediterranean Sea. 59 Tomahawk missiles targeted the Shayriat Syrian Air Force airfield. The strike was described by the US Department of Defense as “a proportional response to Assad’s heinous act”. It was also added that the Airfield “was used to store chemical weapons and Syrian air forces” and that “[t]he U.S. intelligence community assesses that aircraft from Shayrat conducted the chemical weapons attack on April 4”. Finally, according to the same statement, “[t]he strike was intended to deter the regime from using chemical weapons again”.
The US President’s decision to attack was neither authorized by the UN Security Council nor did it have Congressional backing in the US. That notwithstanding, it was met favorably by a large number of States, with statements ranging from open support for the attack to statements qualifying the US reaction as “understandable”. However, legal scholars expressed severe doubts as to the legality of the action.
On 7 April, a press release by the Ministro degli Affari Esteri e della Cooperazione Internazionale (Minister for Foreign Affairs and International Cooperation), Mr. Angelino Alfano, clarified the Italian position on the matter. The relevant part of the press release reads:
Italy understands the reasons of a US military action, proportionate in time and manner, in response to an unacceptable sense of impunity and as a sign of deterrence against the risk of a further use of chemical weapons by Assad, in addition to the cases already ascertained by the United Nations. The air raids conducted on Khan Sheikhoun on 4 April were ruthless and cruel for the high death toll they caused, including many children. They are vile actions that Italy and the European Union have firmly condemned and that add on to Assad’s reiterated violations of the ceasefire and the atrocious violence repeatedly perpetrated by his Armed Forces on civilians. Our Government is closely following the events unfolding in the Mediterranean, in consideration of its many and direct interests in the security and stability of the region. It is now necessary and urgent to reactivate the UN Security Council and make it fully functional in reaching a consensual resolution in order to identify the parties responsible and avert future atrocities. As a member of the Security Council, Italy will continue to work towards this end. Moreover, Italy strongly wishes for the international community to resume its commitment – on the basis of a renewed USA–Russia dialogue – to achieve a UN-led political transition in Syria in compliance with Resolution 2254 of the UN Security Council and the 2012 Geneva Communiqué.
Subsequently, on 10-11 April, Italy hosted the G7 Ministerial Meeting on Foreign Affairs. Understandably, the attention of the Ministers focused inter alia on the situation in Syria and their “Statement on Non-Proliferation and Disarmament” made direct reference to the facts of Khan Shaykhun. In their joint statement, the Ministers affirmed:
We are shocked and horrified by the reports of use of chemical weapons in an airstrike in the Khan Shaykhun area of southern Idlib on 4 April. Syria’s possession of chemical weapons and their means of delivery are illegal under UN Security Council Resolution 2118 and the Chemical Weapons Convention. The subsequent US military action against Shayrat Airfield was a carefully calibrated, limited in scope response to this war crime and was directed against Syrian military targets directly connected to the 4th April chemical weapons attack in order to prevent and deter the proliferation and use of deadly chemical weapons in Syria.
Somewhat paradoxically, after having endorsed the US military action, the G7 statement also expressed full support for the OPCW Fact Finding Mission which should have identified the perpetrators and called upon “the Syrian Arab Republic and all parties in Syria to cooperate fully with the OPCW to allow a prompt conclusion of its investigation on this heinous incident”.
 “Death toll rises in Syria ‘gas attack’”, Deutsche Welle, 4 April 2017, available here.
 Report of the OPCW Fact-Finding Mission in Syria regarding an alleged incident in Khan Shaykun, Syrian Arab Republic, April 2017, Annex to Letter dated 30 June 2017 from the Secretary-General addressed to the President of the Security Council, UN Doc. S/2017/567, paras. 1.7 and 5.80.
 Seventh report of the Organisation for the Prohibition of Chemical Weapons–United Nations Joint Investigative Mechanism, Annex to Letter dated 26 October 2017 from the Leadership Panel of the Organisation for the Prohibition of Chemical Weapons–United Nations Joint Investigative Mechanism addressed to the Secretary-General, UN Doc. S/2017/904, para. 46.
 “Attaque au gaz toxique en Syrie: la communauté internationale met en cause Assad et ses soutiens”, Le Monde, available here.
 “Statement from President Donald J. Trump”, 4 April 2017, available here.
 “Observatory says 58 killed in suspected chemical attack in Syria, military source denies”, Reuters, 4 April 2017, available here.
 “Remarks by Russia’s Permanent Representative at the OPCW, Ambassador Alexander Shulgin, at the 54th Meeting of the OPCW Executive Council”, 13 April 2017, available here. This Russian narrative was however quickly dismissed when it was shown that there was no evidence of any buildings being hit in the area. See “‘The dead were wherever you looked’: inside Syrian town after gas attack”, The Guardian, 6 April 2017, available here.
 “Security Council Fails to Adopt Resolution Condemning Chemical Weapons Use in Syria, Following Veto by Russian Federation”, Press release of 12 April 2017, SC/12791.
 US Department of Defense, “Statement from Pentagon Spokesman Capt. Jeff Davis on U.S. strike in Syria”, available here.
 For example, the statement issued on 7 April 2017 by the German Minister for Foreign Affairs, Sigmar Gabriel: “It is understandable that the United States has now responded with an attack on the military structures of the Assad regime which were the source of this horrific war crime”, available here. For an overview of the position of States on the attack, see: “Which Countries Support and Which Oppose the U.S. Missile Strikes in Syria”, The New York Times, 9 April 2017, available here.
 Ku, “Trump’s Syria strike clearly broke international law – and no one seems to care”, Vox, 19 April 2017, available here.
 The statement is available here. On 12 April 2017, the Minister expressed the same concepts in Parliament, during a communication before the Senato della Repubblica (Senate of the Republic, 807th Meeting, XVII Legislature).
 G7 Statement on Non-Proliferation and Disarmament, Lucca, 11 April 2017, available here.