Was the Turkish downing of the Russian Su-24 fighter jet over Syrian territory an act of pure recklessness taken at a moment of uncontrolled anger, or was it coolly and calculatedly planned ahead of time with consideration of the potential consequences? Was it a purely Turkish decision, or was there advance consultation with Turkey's partners in NATO? Will the concerned powers be able to rein in the fallout from this act and safeguard the horizons for a peaceful settlement to the Syrian crisis? Or was the act intended to destroy those horizons and sabotage the road to the Vienna conference? The information that is currently available on the circumstances and motives behind the downing of the Russian aircraft is not sufficient to offer clear and precise answers to the foregoing questions, which are both legitimate and important. Nevertheless, this deficiency should not deter us from an attempt to examine the causes and significances of this sudden and dangerous turn in the course of the Syrian crisis. As we engage in this effort, our first concern should be to avoid falling into the trap of legal details. Most of the dispute so far has revolved around whether the Russian fighter plane violated Turkish airspace and whether Turkey issued warnings before opening fire (the grounds that Turkey cites to support its claim that it was acting in self-defence, and to safeguard its territorial sovereignty), or whether the Russian bomber did not violate Turkish airspace, had not received warning signals and was downed over Syrian territory (the grounds that Russia cites in support of its claim that the downing of its plane was an act of aggression and an act of war). To me, this type of debate seems futile for two chief reasons. First, for Turkey to shoot down a military aircraft belonging to a major power such as Russia is a very dangerous act by all standards, even supposing that the Turkish claim that that plane violated its airspace for a few seconds were true. Therefore, the decision must have been motivated by other reasons that are important to discover and identify. Second, Russia may not have taken sufficient pains to avert that incident and, afterwards, it did not try to contain the fallout. In fact, it strived to capitalise on it as an additional justification for escalation. The reasons and ramifications of this also need to be determined. In such a context, it is not unlikely that Turkey had been lying in wait with its finger on the trigger as Russian fighters performed their missions over areas of Syria inhabited by Turkmen tribes. If so, it had taken a premeditated decision to shoot down a Russian military jet in the manner of a calculated risk to test the firmness of the Russian position in support of the Bashar Al-Assad regime. Nor can we rule out the possibility that Russia, which was mostly likely taken by surprise by the incident, decided to use it as an excuse for notching up pressure on Turkey to compel Ankara to change its policies on Syria. As the developments of the Syria crisis have propelled both Moscow and Ankara to adopt strategies that are so different as to be virtually antithetical, it is also likely that the incident, if we accept the premises of a Turkish calculated risk and a Russian calculated response, is part of a larger game of political brinksmanship being played by both sides. Naturally, such an approach is highly dangerous, but still this is not the only theoretical paradigm capable of explaining developments in the relationship between the two countries. It is very unlikely that Turkey took any decision on its own, without having consulted in advance with its partners in NATO, the US above all, over the matter of pursuing a policy of brinksmanship against a major power such as Russia. Still, this does not signify that the US and Turkey have adopted a unified policy toward the Syrian crisis, or that they are coordinating actions to counter Russia's growing influence in this region's affairs. Russia, for its part, has been manoeuvring to fill the vacuum resulting from the reluctance of the Obama administration to perform the roles previous US administrations have played in the Middle East. Moscow has sought to seize all available opportunities to increase its influence in the region, especially the opportunities produced by the Syrian crisis. The US is naturally disturbed by Russia's growing influence, but the level of its concern is still a long way from Ankara's anger over the Russian intervention in Syria. It follows that Washington and Ankara have clearly divergent positions on the future course to take toward the Syrian crisis, even if the two countries are officially allies in NATO, or in the framework of the US-led coalition against Islamic State (IS). At another level, it is important to note the US's awareness of the mounting threat posed by terrorist groups, especially since IS seized control over large tracts of Iraq and Syria. However, Washington's determination not to introduce US troops on the ground to combat these terrorist groups forces it to rely on existing forces on the ground. As most of these are either Shia or Kurdish, which Ankara finds disagreeable, the gap between the two countries over how to handle the Syrian crisis broadened. If we add to the foregoing the shady relationship between the Turkish ruling party and certain factions of the Syrian opposition that some of the US's allies in the region regard as extremist if not terrorist, we can appreciate the magnitude of the complications surrounding the process of coalition-building in the Middle East. IS's success in carrying out a major terrorist attack in Paris on 13 November has, moreover, further complicated the process of building international anti-terrorist coalitions in this part of the world. One of the effects of that operation was to drive Russia and France closer together while creating distances between France and the US and France and Turkey, especially as concerns evaluations of the situation in Syria and positions on the Bashar Al-Assad regime. As Russia has shifted from being one among a long list of influential international players in the Syrian crisis to the role of a superpower seeking to lead a more effective international coalition against IS, Turkey has become increasingly nervous over the growing Russian influence, to the extent that it has presented itself as a natural candidate to lead, in cooperation with Saudi Arabia and Qatar, an alternative coalition to that currently being led by the US. Clearly, the Middle East is headed for some dramatic developments in the forthcoming months. After the IS bombing of a Russian passenger plane over the Sinai and Turkey's downing of the Russian Su-24 over Syrian territory, and after IS's move to stage terrorist attacks against restaurants, football stadiums and theatres in Paris, and Al-Qaeda's attack against the Radisson Blu Hotel in Mali, it is only natural that the entire world feels alarmed and refuses to allow the situation in this part of the world to continue in its current state of tumult. But as strong as the desire to act is, it is impossible to predict the consequences of the action. One of Russia's responses to Turkey was to deploy an S-400 air defence system, said to be capable of protecting Syrian airspace from hostile aircraft. The intent, of course, is to deter Turkey from staging another attack against its aircraft and, simultaneously, to help the Syrian army move with greater ease to its targets by providing stronger air cover. Meanwhile, France, which has vowed to eliminate IS, is lobbying other European countries to muster more active participation in the war against that terrorist organisation. Towards this end, it is campaigning to build an international coalition from which Russia cannot be excluded. Russia, for its part, cannot enable its ally, the Syrian regime, to score a decisive victory over the opposition, be they extremists or moderates. But nor do I think that this is the aim that it seeks to accomplish. Rather, I believe that Moscow, together with France, is working towards, and may be capable of, coordinating international efforts with an eye to reaching a balanced political settlement in Syria that will allow the moderate opposition to take part in governing Syria while safeguarding the country's territorial integrity and paving the way for the total elimination of extremist organisations. The Russian position is not without considerable risks. There are international and regional powers that will remain relentless in their determination to drag Russia deeper into the Syrian quagmire. We can therefore expect the coming months to bring an increasingly fierce competition between these two strategies. As for the Syrian people, they will continue to pay, perhaps for many years to come, the exorbitant costs of this deadly rivalry at the international and regional levels. The writer is a professor of political science, Cairo University.