That's a great question as Solzhenitsyn wanted an ethnic Russia which occupied Belarus, half the Ukraine and the northern chunk of Kazakhstan. - Sometimes Metternich, Comment #5Response by Stratfor:
Russia — modern, medieval or otherwise — cannot count on natural features to protect it.... That leaves buffers. So long as a country controls territory separating itself from its foes — even if it is territory that is easy for a hostile military to transit — it can bleed out any invasion via attrition and attacks on supply lines. Such buffers, however, contain a poison pill. They have populations not necessarily willing to serve as buffers. Maintaining control of such buffers requires not only a sizable standing military for defense but also a huge internal security and intelligence network to enforce central control. And any institution so key to the state’s survival must be very tightly controlled as well. Establishing and maintaining buffers not only makes Russia seem aggressive to its neighbors but also forces it to conduct purges and terrors against its own institutions in order to maintain the empire. - George Friedman, Stratfor
Solzhenitsyn's borders never happened. They would have left Russia vulnerable from the South - through the Caucasus Mountains and up the Steppes - and from the West - along the Northern European plain. Russia's solution, as noted by Dr. Friedman, is control of buffer zones in the West, East, and South, with hostile populations. In Why Chechnya First?, Metternich and I concluded that Putin was trying to re-establish the buffers lost in 1990, beginning with a region both important and within the Russian Federation's borders.
Was this necessary? Were they following a strategy that had become obsolete? The buffer strategy contains an unstated assumption that the benefit of the buffers outweighs the cost of the hostile populations. When French cavalry or German tanks come marching East, that assumption was correct. I do not think this holds true today.
Technology has changed the equation, both the costs and the benefits.
On the one hand, the cost of controlling a hostile population has risen considerably. While technology does aid the suppression of dissent, it has a much greater effect in increasing the capabilities of an insurgency to do greater damage, further from home.
On the other hand, the benefit of a buffer zone has decreased in two ways. First, a nuclear state cannot currently be conquered. Second, a modern army would have a much easier time crossing the buffers than either the First French Empire or the Third Reich. Both the necessity and the utility of the buffers has decreased.
So could the Russian Federation retreat to Solzhenitsyn's borders? Would that have been a smarter move for Putin? Rather than an attempt at the ressurection of a Russian Empire, should he have pursued an ethnic Russian Republic? Perhaps. SIM.