The old Russian reserve system looked impressive on paper but was a mess when actually used. At the end of the Cold War, Russia had over 150 combat divisions in its army. But only a third of these were at full strength in peace time, the rest were reserve divisions. The Russians planned to mobilize over two million men to fill out their reserve divisions in wartime. The Russians maintained their reserve divisions with a skeleton crew of active duty soldiers.
In theory, this could work, but rarely worked well for Russia. In 1914 the Germans demonstrated to their disbelieving opponents that reserves could be as effective in wartime as regulars. The Germans did this by requiring their reserves to train regularly, much like the current American system. Russia could not afford this, although attempts were made to do some training. Most Russian reservists were assigned to a unit they had never seen and never would see unless they were called up. Russia called up reservists when they invaded Afghanistan in 1979, but quickly removed these reserve troops and replaced them with regulars. The reservists just weren't very effective.
Before 1991, Russia maintained an additional fifty divisions on paper, to be raised in wartime from reserves and obsolete equipment held in storage. These units, with troops in their thirties and forties using equipment as old as they are, will be no match for an equal number of active divisions. But such "mobilization" divisions can make a difference, if you believe that quantity has a quality all its own.
The Russian System kept track of every veteran until the age of fifty. That was their reserve manpower, and about all they did was keep track of current mail addresses. Many nations still use the same general concept for their reserves. Unable to afford the expense of regular reserve training, the usual source of men with current experience are those discharged in the last few years. Russia has used conscription for over a century, and during the Cold War, there was a constant supply of recently discharged men. That reduced Russia's reserve to a million men times the number of years you want to go back- say two to five million men. This was a major flaw in the Russian system, as it has been found that soldiers lose most of their military skills within a month of leaving active service. It takes several months to get these skills back. If troops are sent into combat before they have been retrained, their units will do very poorly against a better trained opponent.
The Russian system, based on the one developed in 19th century Germany, was suitable for a nation lacking great wealth. It was cheap, because it had to be. In Russia, a reservist may not be called up for more than ninety days a year unless a national emergency is declared. This is not done out of any regard for the reservist but in recognition of the labor shortage and economic disruptions that would be created. Most reservists are never called up.
An example of the problems inherent in this system could be seen in the Russian mobilization against Poland in 1980. In areas adjacent to Poland, Russia had 57 divisions. At least 40 would be needed to guarantee a quick conquest of an increasingly uncooperative Poland. Of the 57 available divisions, only 28 were fully manned and 24 of those were occupying East Germany and Czechoslovakia. Because of possible unrest in Eastern Europe, or interference from Western Europe, the divisions in East Germany and Czechoslovakia were left alone. This forced the use of 36 reserve divisions and bringing most of them in from other areas. Over half a million men would have to be called up. This would have a noticeable effect on the local economy, as over 50 million man days would be lost. In addition, there would be the expense of maintaining the troops and the loss of civilian trucks taken by the army for activated reserve divisions. This strain on the local economy was one of the critical, but not mentioned, factors causing Russia to demobilize and not attempt to pacify Poland by invading. Russia made it appear that they were being diplomatic but they were faced with causing enormous economic disruption in Russia areas adjacent to Poland, and that could have led to unrest in Russia itself.
Economic disruption is not the only problem Russian style mobilization armies face. These armies rely heavily on conscripts, to the extent that 75 percent of their manpower are two or three year draftees. Most of the noncommissioned officers were conscripts of dubious quality. Russian officers are all volunteers and graduates of military academies. These officers perform the tasks normally assigned to NCOs in Western armed forces. Supervision, management and leadership of Soviet troops was inadequate in peacetime and became even more scarce when millions of reservists were mobilized. The mobilized army is about 85 percent conscript, with the rate going over 90 percent in a third of the divisions. If history is any guide, this third of the Russian Army was probably less than half as effective as the top third.
The solution to these quality problems is training. Most Western armies train their reserves, or attempt to. Training is critical because an effective soldier is very much a technician. The effective maintenance and use of weapons and military equipment is possible only with constant practice. Reserves that do not regularly practice require one or more months to regain their skills. Personnel with prior military service are easier to whip into shape for combat because of their familiarity with military routine. Because of their prior service, reserve troops have demonstrated an ability to function in a military environment. However, one should not place too much reliance on prior military experience. Unless these troops maintain good physical conditioning and some knowledge of their military skill, they are not a great deal better than raw civilian recruits.
The old Russian reserve system provided large numbers of troops but very low effectiveness. The Russians were aware of this, being diligent students of past experience. Their solution was to prepare for a short war, short enough so their deficiencies would not catch up with them. This was not to say that Russia could not win a long war. They were victorious during World War II, but at a cost of 30 million dead (18 percent of the population) and a ruined economy. Many of those losses were the result of sending newly mobilized reservists out to face German combat veterans.
Times have changed. Nuclear weapons make it unlikely that anyone would try to mount a major invasion of Russia. Trained reservists would be useful for a local rebellion or natural disaster. This is how they have successfully been used in the United States and other Western nations. Russia wants some of that and believes it will be able to afford to build it in the next decade.