MOSCOW âÂ Russia on Monday angrily condemned the downing of a Syrian aircraft by a U.S. fighter as a âflagrant violation of international law,â and said its forces will treat U.S.-led coalition aircraft and drones as targets if they are operating in Syrian airspace west of the EuphratesÂ while Russian aviation is on combat missions.
The Russian Defense Ministry also said it is suspending an agreement to minimize the risk of in-flight incidents between Russian and U.S.-led coalition aircraft operating over Syria.
Russia, which has provided military support to Syrian President Bashar al-Assad since 2015, was reacting to U.S. military confirmation that a U.S. F-18 Super Hornet shot down a Syrian Su-22 fighter-bomber Sunday. The Syrian jet had just dropped bombs nearÂ members of the Syrian Democratic Forces, or SDF,Â a militia aligned with the U.S. militaryÂ in the campaign against the Islamic State.
In a statement Monday, the SDF warned that it would retaliate in the face of further aggression from pro-Assad forces, raising the possibility that the United States could be forced to deviate further from its stated policy in Syria, which only involves targeting Islamic State militants.
On Monday, the Russian Defense Ministry said its warplanes had beenÂ operating in the area of the encounter between the U.S. and Syrian jets. The ministry said the coalition had not used the deconflicting hotline to warn Russian forces.
âMultiple military actions of U.S. aviation under the guise of fighting terrorism against the legal military of a state that is a member of the United Nations are a flagrant violation of international law and constitute de facto military aggression against the Syrian Arab Republic,â the ministry said.
âWe view these actions by the American command as a conscious failure toÂ uphold their responsibilities within the memorandum,â the ministry said.
Russia briefly suspended the 2015 memorandum of understanding on the air operations after U.S. forces fired Tomahawk missiles at a Syrian air base in April.
Â Also on Monday, a senior Russian diplomat warned that the downing of the Syrian jet wasÂ âyet another step in a direct and dangerous escalation.âÂ
âWe are warning Washington not to take such actions in the future,â Deputy Foreign Minister Sergei Ryabkov told the Interfax news agency.
The confrontation took place late Sunday near the northern city of Tabqa, hours after Syrian government forces harassed a U.S.-backed local ground force with airstrikes.Â
It was the first time that the American military has shot down a Syrian warplane during the six-year conflict. The incident followed a series of U.S. airstrikes against Iran-backed forces advancing on partner forces in a strategically prized swath of land along the Iraqi border.Â
Outside observersÂ said Sundayâs strike underscored a growing willingness on the part of Assadâs forces to confront the U.S.-led coalition as they jostle to roll back Islamic State militants from eastern Syria.Â
That effort has been bolstered by the freeing up of thousands of Shiite militiamen who had fought in a campaign across the border to capture the city of Mosul from Islamic State militants.
âThe wild card here is the logic of an Assad regime which has decided that it no longer wants to be constrained to a Western Syria-based statelet,â said Nicholas A. Heras, a fellow at the Washington-based Center for a New American Security.
ThatÂ shift has been driven by an assessment that the TrumpÂ administration couldÂ use the territory its forces capture as a bargaining chip with which to push Assad into a political transition or Syria into a decentralized political system, Heras added.Â Â
In Moscow, officials argued that Sundayâs shoot-down was intended as a message aimed squarely at them.
Franz Klintsevich, deputy head ofÂ the defense and security committee of the Russian upper house of parliament, called the incidentÂ âan aggression and a provocationâ directed at Russia.Â
âIt looks like Donald Trumpâs United States is a source of a brand-new danger both in the Middle East and the world at large,â KlintsevichÂ wrote on his Facebook page.Â
Another member of the upper house, Alexei Pushkov,Â tweeted that the incident was âa new act of warâ against the Syrian government.Â
The upper house, the Federation Council, is a largely toothless body that essentially carries out Russian President Vladimir Putinâs policies with little opposition.
The reaction of Russiaâs foreign minister, Sergei Lavrov, was more muted. Russiaâs top diplomat said the United States should respect Syriaâs territorial integrity and that any actions on the ground âshould be coordinated with Damascus.â
âWe call on the United States and all others who have their forces or their advisers âon the groundâ to ensure coordination in our work,â the official Russian Tass news agency quoted Lavrov as saying at a meeting with the foreign ministers of Brazil, India and China in Beijing.
Putin said last week that Syria has proved to be a useful testing ground for advanced Russian weapons systems.Â
âIt has done enormous good for our defense industry,â Putin told Russians in his annual televised call-in show. âI can say that the experience our armed forces have gained under combat conditions, especially with the use of cutting-edge weapons, is invaluable.âÂ
Loveluck reported from Beirut.