U.S. President Donald Trump (R) shakes hands with Greek Prime Minister Alexis Tsipras at the family photo session during the North Atlantic Treaty Organization (NATO) summit in Brussels, Belgium, on July 11, 2018. The North Atlantic Treaty Organization (NATO) summit began Wednesday in Brussels with verbal fireworks as recent tensions between allies and the United States were laid bare by U.S. President Donald Trump in a growing row over burden sharing and foreign influence. (Xinhua/Ye Pingfan)