Because of problems getting enough soldiers to volunteer for duty in Syria Russia is changing its laws regarding the use of contract soldiers (higher paid volunteer troops) so that they can use contracts of a year or less for soldiers who will serve overseas, namely in Syria. The current law on contract soldiers only allows short-term contracts in exceptional circumstances like natural disasters or civil unrest in Russia. The standard contracts for volunteer soldiers is five years for officers and senior NCOs and two or three years for lower ranking soldiers. Russia is apparently using bonuses for Russian soldiers serving in Syria but that has not proved sufficient to get the number of troops needed.
Russia has only sent a few thousand ground troops to Syria but these are some of the best troops Russia has and ISIL (Islamic State in Iraq and the Levant) and the other Islamic terrorist rebels will suffer much heavier casualties if they clash with these Russians. This not only keeps Russian casualties down but also boosts morale among Syrian troops and civilians in government (Assad) territory and makes it more likely that a Russian and Iranian efforts to keep the Assads in power, even if it means a partition of Syria, will be more acceptable to the world.
Since the beginning (mid-2015) Russia always maintained that it was sending only “volunteers” to Syria and this is technically true. This is a policy adopted in Ukraine, and for good reason. While “acting strong” is popular with most Russians, the risk of your own conscripted sons getting sent to Ukraine or Syria and killed or maimed is definitely not popular. To the dismay of Russian leaders it was found that even when young volunteer (“contract”) soldiers get hurt there is popular backlash. This despite government willingness to pay compensation (not a Russian tradition) to families of the dead as well as to disabled soldiers.
Thus Russia has an incentive to rely a lot on tech and mercenaries (mainly supplied by Iran) to avoid Russian casualties. Even though Russia keeps its casualties down in Syria serving there has not attracted enough of the high quality Russian troops (pilots, commandos, tech experts, trainers and advisors) that are needed. The short contract option enables the government to approach any qualified (for Syria service) military personnel and offer that a lucrative contract for a year or less to go overseas. Many families see this as no worse than similar short term-contracts for civilian jobs like working in remote places as pilots or taking part in construction projects.
The contract soldiers have been useful, but expensive, since they were first introduced in the early 1990s. Many Russians wanted an all-volunteer military but that was unaffordable. The number of kontraktniki (contract) soldiers increased as money was available. There were also political aspects to this. Thus in 2013 the Russian government bowed to public pressure and agreed not to send conscripts into combat. Only contract soldiers will do combat, unless there is a general war. As a result of this 2013 policy, combat training of conscripts was reduced from six to four months. Actually, training was cut in half, but conscripts were to not be sent to a combat zone (as in the Caucasus) until they had been in uniform for at least four months. The actual wording of these new regulations allowed conscripts to be sent to do non-combat jobs in the Caucasus, where terrorism is quite common. This was not publicized. These new rules were issued with no fanfare but the word quickly got around and parents of draft age (18-26) men were outraged. This was seen as a subterfuge to save money (less training for draftees) at the expense of the young conscripts and still send them to dangerous service in the Caucasus. While the conscripts would not be chasing after Islamic terrorists down there, they would be targets for terrorist attacks and would, because of the training cuts, be less able to defend themselves. The parents figured that out themselves. The military saw the change as necessary because conscripts are only in for a year now, rather than two and extensive training is costly and largely wasted because most of the conscripts leave after their year is up. The larger problem is that Russia has fewer and fewer people to conscript and a very difficult time attracting volunteers. A year later there was a demand for “volunteers” in Ukraine, which was technically now overseas. The new short-contract law helps with getting enough volunteers for Ukraine as well.
By 2013 the Russian the military had 220,000 officers and 200,000 "contract personnel" mainly to fill most of the NCO and specialist slots. Thus most of the troops are conscripts, and it's getting harder and harder to find enough people to coerce into uniform. The armed forces needs over 600,000 conscripts a year but can only obtain about 400,000, and that number is declining each year. Most of the missing troops were young men who were conscripted but never showed up. The barracks are thinly populated and the situation is becoming a major national scandal. So now it is generally agreed among the generals that conscription has to go and better troop supervision (via competent sergeants) has to be established. Russians note with fear that the Chinese now have an army three times the size of theirs and spend three times as much on defense. China is also building an effective NCO corps, something that has long made Western forces much more effective.
The current plan is to increase the number of contract troops to 425,000 over the next few years and use a special six week training and selection program, to make sure the right people are signed up. The six week course is a series of training and testing sessions that determine if candidates can handle the stress of military life and possess enough maturity to avoid the traditional abuse inflicted on new troops and help stop those who are still bullying their fellow soldiers. These new contract soldiers are also selected on the basis of willingness to make a career of the military and eventually take on more responsibilities (becoming NCOs, technical specialists or officers). To meet the goal of 425,000 contract soldiers the military will have to bring in 50,000 new contract soldiers a year. That goal is not being achieved mainly be army service is so despised that even competitive (with civilian jobs) pay and better living conditions is not attracting as many qualified volunteers as needed.