Moscow's ties with the Islamic Republic of Iran underwent dramatic fluctuations following Ayatollah Ruhollah Khomeini's triumphant return to Tehran in 1979. After a prolonged implosion, they fitfully expanded, shaped not only by the rush of current events but by centuries of ingrained practices and prejudices. By summer 2006, as Iran forged ahead with its nuclear program and Shia-based forces flexed their muscles across the Middle East, Russian-Iranian relations again appeared to be on the threshold of an entirely new dynamic. Drawing on firsthand interviews as well as primary and secondary sources, John Parker delineates Moscow's motives and approaches to dealing with the resurgent Tehran, weaving into the public record the recollections and analyses of Russian politicians, diplomats, and experts who dealt directly with Iran both under the Pahlavi monarchy and after the 1979 Islamic Revolution. Parker also emphasizes other touchstones of relations between the two countries, including their complex dealings in 1992 immediately after the Soviet Union's collapse and when they backed opposing sides in the civil war in Tajikistan yet nourished mutual interests on other issues. The depth of his analysis sheds light on the more recent repercussions of the September 11 terrorist attacks for Afghanistan and Iraq, for the Middle East as a whole, and for Iran's accelerating nuclear program.