Congressional Democrats and Foreign Service workers are condemning the Trump administration’s plans to withdraw the U.S. from the Open Skies Treaty, which allows member states to carry out unarmed surveillance flights over each other’s territories to verify arms control agreements. In a letter to the White House Monday, House Foreign Affairs Committee Chair Eliot Engel warned any withdrawal would benefit Russia, which annexed Crimea after invading Ukraine in 2014. Congressmember Engel wrote, “Observation flights under the treaty have generated additional information regarding Russian military action in Ukraine and provided a check on further Russian aggression there.” This comes just two months after President Trump formally withdrew the U.S. from the Intermediate-Range Nuclear Forces Treaty with Russia, the landmark 1987 agreement banning all nuclear and non-nuclear missiles with short and medium ranges.