In its long [[history]], Europe has been at peace only when its major powers have all been included in a cooperative security system. The [[Concert of Europe]] kept the European peace for a century. The exclusion of [[Germany]] and the USSR from the councils of Europe in the 1920s and 1930s catalyzed [[World War II]] and the [[Cold War]]. The attempted exclusion of Russia from a role in the maintenance of [[peace]] and [[security]] in Europe in the 21st century has deprived it of [[diplomatic]] alternatives to a relapse into [[belligerent]] behavior. | In its long [[history]], Europe has been at peace only when its major powers have all been included in a cooperative security system. The [[Concert of Europe]] kept the European peace for a century. The exclusion of [[Germany]] and the USSR from the councils of Europe in the 1920s and 1930s catalyzed [[World War II]] and the [[Cold War]]. The attempted exclusion of Russia from a role in the maintenance of [[peace]] and [[security]] in Europe in the 21st century has deprived it of [[diplomatic]] alternatives to a relapse into [[belligerent]] behavior. |