Trump orders. He is the only US President who dared hitting Russian forces like that. Indeed Trump was the toughest on russia.
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Trump Orders Missile Attack in Retaliation for Syrian Chemical Strikes
https://www.defense.gov/News/News-Stories/Article/Article/1144601/trump-orders-missile-attack-in-retaliation-for-syrian-chemical-strikes/
U.S. Military Killed ‘A Couple Hundred’ Russians In Syria Airstrikes, Pompeo Says As Trump Considers New Attack
https://www.newsweek.com/us-military-killed-200-russians-syria-airstrikes-pompeo-says-trump-considers-883947