Companies are just beginning to learn what nations have always known: in a complex, uncertain world filled with dangerous opponents, it is best not to go it alone. Great powers operating across broad theaters of engagement have traditionally made common cause with others whose interests ran parallel with their own. No shame in that. Entente—the striking of an alliance—is a responsible part of every good strategist’s repertoire. In today’s competitive environment, this is also true for corporate managers.

A version of this article appeared in the March–April 1989 issue of Harvard Business Review.