Book excerpt: Undeclared Wars with Israel examines a spectrum of antagonism by the East German government and West German radical leftist organizations - ranging from hostile propaganda and diplomacy to military support for Israel's Arab armed adversaries - from 1967 to the end of the Cold War in 1989. This period encompasses the Six-Day War (1967), the Yom Kippur War (1973), Israel's invasion of Lebanon in 1982, and an ongoing campaign of terrorism waged by the Palestine Liberation Organization against Israeli civilians. This book provides new insights into the West German radicals who collaborated in 'actions' with Palestinian terrorist groups, and confirms that East Germany, along with others in the Soviet Bloc, had a much greater impact on the conflict in the Middle East than has been generally known. A historian who has written extensively on Nazi Germany and the Holocaust, Jeffrey Herf now offers a new chapter in this long, sad history.