The Eurasian Hordelands are wide-open – unblemished by large lakes, mountains or really anything at all that impedes movement (aside from sheer distance, of course). In this world-at-night picture, one can easily see how the Russians have absolutely no geographic barriers they can hunker behind anywhere near their Moscow home (the bright cluster in the upper left). For Russia to be safe, it has to expand to geographic barriers far from home. Some are fairly simple, such as the Central Asian deserts (the large dark areas in the lower right).
Others are more complicated. The Caucasus is a great barrier, but there are two problems. First, should the Russians achieve a forward-holding position in the Caucasus, they are then perched at the very edge of Turkish, and especially Persian, territory. The mountains cannot be everyone’s buffer zone.
Second, people live in the Caucasus. Some, like the Chechens (the capital of Groznyy is the easternmost bright spot on the northern slope), viscerally resist Russian power. Others, like the Azerbaijanis (the bright finger of light jutting into the west coast of the Caspian Sea), attempt to walk a tightrope between the larger powers that surround them.
The alignment – or occupation – of places such as bright Baku may well prove to be the key to Turkish, Iranian and Russian ambitions.
For more on how the struggle for the Caucasus will unfold, see Chapter 9 of The Accidental Superpower.