In "The 51 Day War" (2015), Blumenthal writes that he was in Gaza during and following Operation Protective Edge, the Israeli military offensive in Gaza during the summer of 2014. Blumenthal said that the catalyst for the military offensive was the kidnapping and murder of three Israeli teenagers by a Hamas cell. He stated that the Israel's West Bank operation was not aimed at rescuing the teens, who were known to be dead, or capturing their killers, but destroying a political agreement between Hamas and the Palestinian National Authority by targeting the Palestinian Unity Government. The book is based on his own observations and interviews with citizens, physicians, and others. He writes that, during the operation, Israel targeted Palestinian civilians and media organisations, conducted execution-style killings and attacked refugee shelters.