VALLETTA, MALTA - NOVEMBER 11: (L-R) British Prime Minister David Cameron and Home Secretary Theresa May attend a remembrance service on HMS Bulwark during the Valletta Summit on migration on November 11, 2015 in Valletta, Malta. The Summit will bring together representatives from the European Union and African countries to address the challenges and opportunities of the largest migration of people to Europe since World War II.  (Photo by Ben Pruchnie/Getty Images)