From the moment the Soviet Union collapsed in 1990, the United States has relentlessly pursued a strategy of encircling Russia, just as it has with other perceived enemies like China and Iran. It has brought 12 countries in central Europe, all of them formerly allied with Moscow, into the NATO alliance. US military power is now directly on Russia’s borders. It is as if Russian nuclear missiles were poised along the borders of Canada and Mexico. ‘’I think it is the beginning of a new cold war,’’ warned the renowned diplomat George Kennan, the renowned diplomat and Russia-watcher, arguably the most insightful Russia-watcher the United States has ever produced, as NATO began expanding eastward. ‘’I think the Russians will gradually react quite adversely, and it will affect their policies.” Russia’s dispatch of troops in recent days to Crimea — a verdant is peninsula on the Black Sea that is part of Ukraine but, as a result of Stalin-era ethnic cleansing, has a mainly Russian population — was the latest fulfillment of Kennan’s prediction. It is also, however, a sign of weakness. The Americans realize this, and are pressing their anti-Russia campaign. Last week President Obama received the prime minister of Georgia. The prime minister of Moldova is due this week. These meetings are aimed at honing a strategy for further isolating Russia; it is called “Western integration.”