Look at this phrasing: why insert "but"??

"Mr. Miliband, who would become the first Jewish-born prime minister since Benjamin Disraeli in the 19th century, has spoken movingly of his family’s flight from the Nazis and the welcome they found in Britain. But he has been a sharp critic of Israeli policies in the West Bank and Gaza and has pushed the party to recognize Palestine."  The way it is phrased, it implies that his criticisms of Israel clashes with his Jewishness.