Russian President Vladimir Putin announced on March 14 that he would begin withdrawing his main forces from Syria. Russia appears to have deployed about 70 aircraft and more than 4,000 support personnel to protect and maintain the aircraft. It was not a major deployment, but it shifted the situation on the ground. Before the deployment there had been serious discussion that Bashar al-Assad's regime had its back against the wall. That expectation dissolved as Russians carried out attacks against those working to overthrow the regime.
It is unclear why the expectations shifted. It is possible that the limited sorties the Russians flew were sufficient to break the opposition's operational capabilities. It is possible that simply Russia's presence was enough to shift the psychology of the opposition and break their will. It is also possible that the opposition was so fragmented and so fundamentally weak that virtually anything would shatter them.
The question of course remains: Why did the Russians intervene in the first place? Assad's father had been close to the Soviets, and post-Soviet Russia made gestures at continuing the relationship. But Syria was never central to Russian interests, and having any number of other problems, particularly Ukraine, devoting precious resources to solving what from Russia's perspective was a relatively small problem is odd. But when you think about it, it made complete sense, even beyond ensuring Assad's survival.
The first reason Putin intervened in Syria was simply to show that he could. He had two audiences for this: the Russian public and the West, particularly the United States. Deploying an air wing consisting of different kinds of aircraft and then maintaining them in combat operations for months demonstrated that Russia had a significant military capability and was able to deploy it effectively.
In Russia, as in other countries, successful, short military operations generate massive support. It demonstrated to the U.S. that it had the ability and will to intrude into places that the U.S. regards as within its area of operations. It changed the perception of Russia as a declining power to a significant global force. Whether this was true was less important - it needed to appear to be true. And it cannot be denied that there was truth to it.
The second point is much stranger and not fully aligned with the prior reason. The Russians intervened in Syria to bail the U.S. out of a very difficult situation. The U.S. opposed the Assad regime and wanted it replaced by a coalition of opposition forces. It was increasingly obvious that this was not going to happen. Assad might fall but what would replace him was a fractious opposition as much at war with each other as with Assad. This might be preferable to Assad, but the Islamic State was deep into Syria and had already engaged and defeated some of Assad's armored forces - not to mention that IS controls far more territory than any other rebel group. If Assad fell, and if he was replaced by the opposition, it was conceivable they could in turn be replaced by IS. The U.S. was aware that it had constantly underestimated IS, and the possibility of IS in Damascus was both real and unacceptable to the United States.
The United States had a political problem. Not only had it opposed Assad, it had been deeply aligned with anti-Assad factions. It could not suddenly become the protector of the Assad regime. At the same time, the United States, at that moment, could not afford the fall of Assad. The Russian intervention solved the problem for the United States.
Was this a formal deal or merely the unexpected outcome? I doubt that papers were signed but I also doubt that it was unexpected by either side. The Russians certainly knew the American situation in Syria: the U.S. didn't trust its own sponsored opposition, was unnerved by IS and helpless to do what it had to. The Russian intervention followed directly from Moscow's public position and posed no problem for it.
By doing this, in the face of massive American air power, Russia either assumed that it could coordinate with the United States in time or that coordination was discussed in the beginning. The Russians knew they were solving an American problem, and the Americans, for all their rhetoric, knew their problem was being solved. And that bought Russia some points for its problem in Ukraine.
Ukraine is of fundamental interest to Russia. It cannot let Ukraine become part of the Western alliance system - a matter we have extensively discussed. Russia's core interest in Ukraine is military neutralization. Its secondary interests are some degree of autonomy in the east and some settlement on Crimea that gives Russia more extensive rights there than it had before.
Syria was intended to do two things. The first was to demonstrate that Russia was a military power to be taken seriously. Second, it was designed to put the United States in a position where publicly, opposing Russia was seen as too risky, and privately, Russia would be viewed as a partner, not a hostile force. The Europeans already wanted a deal to abandon the sanctions, and this would help.
Syria was not about Syria. The future of Assad was not a major Russian strategic issue. We should not overstate the Russian military achievement. But it was adequate for the political task, which is all that can be asked of it. It did not solve Russia's Ukraine problem, but it did not harm the chances of a negotiated end. In any case, it was well done and, I suspect, not something the U.S. was nearly as appalled by as it pretended to be. The problem for Putin is that it is now over. He must turn it into solutions to strategic problems. And the question is whether this success turns into respect or simply slips between the waters of political memory.