BRUSSELS

Russia's invasion of Georgia is a game changer. This war is part of a Russian strategy of roll-back and regime change on its borders. The more evidence that comes in, the clearer it is becoming that this is a conflict Moscow planned, prepared for and provoked -- a trap Tbilisi unfortunately walked into. A core Western assumption since 1991 -- that Moscow would never again invade its neighbors -- has been shattered. As Moscow basks in its moment of nationalistic triumphalism, the West needs to take steps to prevent...