President Trump on Monday put the brakes on a preliminary plan to impose additional economic sanctions on Russia, walking back a Sunday announcement by U.S. Ambassador to the United Nations Nikki Haley that the Kremlin had swiftly denounced as “international economic raiding.” Preparations to punish Russia anew for its support of Syrian President Bashar al-Assad’s government over the alleged chemical weapons attack in Syria caused consternation at the White House. Haley had said on CBS News’s “Face the Nation” that sanctions on Russian companies behind the equipment related to Assad’s alleged chemical weapons attack would be announced Monday by Treasury...