Seven decades ago, shortly after World War II wound to a close, the American diplomat George F. Kennan wrote a piece in Foreign Affairs magazine on a way for the United States to tackle the Soviet Union that later came to be famously known as "containment policy". Lying between the extremes of appeasement and war, Mr Kennan advocated containment - and a Cold War rather than a hot, military conflict.

In his view, Josef Stalin was not Adolf Hitler, with a fixed timetable for conquering Europe. However, he was determined to dominate the continent. If Soviet expansionism could be contained for a long enough time, and with a coherent strategy, it could eventually even lead to a state collapse because of Soviet society's many internal contradictions, Mr Kennan argued.