How Enemies Become Friends: The Sources of Stable Peace

In a time when optimism about international affairs is low and scepticism is rife about the possibilities of extending international cooperation, Charles Kupchan has written quite a hopeful book. He asks what makes former enemies into friends, and keeps them friends. One influential view sees international politics as ruled by rivalry and fear. No state dare trust another, and if it wishes for peace, must prepare for war. But in many parts of the world, including Europe, which were once subject to repeated and widespread conflict, peace is now the normal state of affairs, and it has become lasting. A zone of peace does not just mean the absence of conflict, but the creation of a state of affairs in which war becomes unthinkable.

Such zones of peace have often been explained as the result of the spread of democracy or the growth of trade. Kupchan agrees that both may be important in consolidating a zone of peace, but argues that they cannot bring it about. That needs a political intervention. The book is devoted to exploring the conditions under which a stable peace between two former adversaries or potential adversaries emerges and becomes enduring.

The first step is the most important. There has to be a unilateral act by the stronger power to accommodate the interests of its weaker rival. This sends a signal that builds trust and encourages a process of reciprocal restraint and dialogue. Kupchan illustrates the process tellingly via the 1990 film The Hunt for Red October, in which the commander of the US submarine, believing that the Soviet submarine he is tracking may defect, exposes his position and by doing so makes himself vulnerable to attack. But this is the key to gaining the trust of his adversary and initiating a process of dialogue that ensures a peaceful outcome.

Once a rapprochement has been established, old adversaries can come to see each other very differently. This is easiest, as Kupchan shows, where states have accountable governments and the checks and balances of a constitutional system, and when their social orders and cultures are compatible. Imagined communities do not only help to create nation states, they also play a crucial role in creating stable zones of peace. But authoritarian governments are also able to make peace, as Brazil and Argentina demonstrated in the 1980s, so long as the stronger power makes a strategic concession to begin the process. If the weaker power makes a concession, it may be interpreted as a sign of weakness, and nothing lasting may result.

Most of the book is taken up with detailed case studies, showing how rapprochement can lead on to security communities and even, in a few instances, to full federal unions. Zones of stable peace are fragile, and gains can be quickly reversed or the process can become deadlocked. Politics is always at the heart of this. The process of European integration has often been regarded as primarily driven by economics rather than politics. But, as Kupchan points out, the economic integration depended on the prior rapprochement between France and Germany. The European Union is currently in trouble, not least over the euro, because economic integration has moved ahead of political integration.

Kupchan analyses a number of examples of rapprochement between former enemies in which conflicts were overcome and a lasting zone of peace created. Particularly telling are the case studies of Britain and the US, Brazil and Argentina, and Norway and Sweden. War is no longer thinkable between these former rivals, and the situation seems as permanent as anything ever is in international politics. The contrast with Greece and Turkey or Israel and Syria is marked. In other cases alliances are formed that seem to herald a lasting relationship but that subsequently break down, such as the Concert of Europe after the Napoleonic Wars, which lasted three decades, and the Anglo-Japanese alliance at the start of the 20th century.

Nothing in this book suggests that the achievement of zones of peace is a one-way street. Friendships can unravel if circumstances change, and conflict can re-emerge, but what Kupchan does show in a rich and persuasive analysis is that parts of the world once riven by conflict have now achieved a stable peace rooted in institutions and identities as well as strategic calculations. The task of extending this process is an urgent one. Eliminating the threat of renewed geopolitical competition is not the only condition for building the cooperative structures that are necessary to tackle the many challenges that human societies face in the 21st century, but it is a necessary one.