Immortal is the only single-volume English-language survey of Iran's military history. CIA analyst Steven R. Ward shows that Iran's soldiers, from the famed "Immortals" of ancient Persia to today's Revolutionary Guard, have demonstrated through the centuries that they should not be underestimated. This history also provides background on the nationalist, tribal, and religious heritages of the country to help listeners better understand Iran and its security outlook.

Immortal begins with the founding of ancient Persia's empire under Cyrus the Great and continues through the Iran-Iraq War (1980-1988) and up to the present.

Drawing on a wide range of sources including declassified documents, the author gives primary focus to the modern era to relate the buildup of the military under the last Shah, its collapse during the Islamic revolution, its fortunes in the Iran-Iraq War, and its rise from the ashes to help Iran become once again a major regional military power. He shows that, despite command and supply problems, Iranian soldiers demonstrate high levels of bravery and perseverance and have enjoyed surprising tactical successes even when victory has been elusive. These qualities and the Iranians' ability to impose high costs on their enemies by exploiting Iran's imposing geography bear careful consideration today by potential opponents.