Russia just mobilized its western regions armed forces, an inevitable response to the growing turmoil in Ukraine. Most westerners are unaware that Ukraine is the cradle of Russian civilization and, when properly run, one of the world’s great producers of grains.

Now that western Ukraine has fallen to anti-Russian, nationalist groups, Russia-oriented eastern Ukraine is also threatening to explode. This nation of 44 million is already de facto split into two parts. How Ukraine’s armed forces respond remains an important question. On Thursday their command vowed to resist any incursion by Russian troops, but loyalties remain uncertain.