Confronted with the human toll of their frequent incursions in the West Bank and Gaza Strip, Israeli officials respond with a familiar, canned refrain: Israel does everything in its power to minimize civilian deaths, and only pursues military campaigns that are consistent with its security needs. Journalist Max Blumenthal’s subversive new book, “The 51 Day War: Ruin and Resistance in Gaza,” a chronicle of Israel’s invasion of Gaza last summer, makes both of these claims difficult to swallow.