An enraged Nikita Khrushchev instructed Soviet ships to ignore President Kennedy's naval blockade during the Cuban missile crisis, but the order was reversed just hours before an inevitable confrontation, according to a new book.

James G. Blight and David A. Welch of Harvard University's John F. Kennedy School of Government say that "if this order had held, war between the superpowers would probably have commenced at sea, shortly after 10 o'clock on Wednesday morning, Oct. 24, 1962, several hundred miles off the coast of Cuba."Anastas Mikoyan, then Soviet first deputy premier, was the catalyst for the reversal of Khrushchev's order, according to the authors. Mikoyan "preempted Khrushchev's order to run the blockade and ordered Soviet ships to stop just short of the quarantine line."

But Blight and Welch said at a news conference Wednesday that it remains unclear whether Mikoyan reversed or circumvented the decision on his own or convinced Khrushchev of its perils. Welch said the order was reversed just hours before Soviet ships reached U.S. forces.

The book, "On the Brink: Americans and Soviets Re-examine the Cuban Missile Crisis," is based on two 1987 conferences sponsored by Harvard - one that featured top Kennedy advisers and U.S. scholars and a second in which three Soviets joined the Americans.

The book will serve as a backdrop for a third conference scheduled for Jan. 27-29 in Moscow featuring, for the first time, Soviet, American and Cuban officials who participated in the crisis, which was triggered when Soviet troops began installing missiles in Cuba capable of reaching the United States.