Two weeks ago, I wrote an analysis of Russian strategy titled "Russia's Move." Here's a brief recap: When the Soviet Union collapsed, it lost control of the western borderlands that had been the bedrock of its security for hundreds of years. Those borderlands created a strategic depth that forced invaders into an extended and exhausting campaign that Russia could resist. Russia had been attacked in the 18th century by the Swedes, in the 19th century by France, and twice in the 20th...