After abruptly pulling U.S. troops who protected Kurdish fighters, President Donald Trump has identified oil protection as the new goal in Syria. But experts question if the new strategy is realistic, or even legal. Defense Secretary Mark Esper said Friday that U.S. troops were reinforcing their positions, including with mechanized forces, in Deir Ezzor in northern Syria. Moscow-based correspondent, Ross Cullen says Russia's frustration is growing over Trump's policy reversal in Syria.