The complexity of the Syrian crisis continues to undermine international attempts at negotiating a peaceful settlement or de-escalation. In 2015, the fighting has accelerated considerably as the so-called Islamic State (ISIS) has continued to hold territory across much of the east and northeast, rebel groups supported by regional powers have made advances in the south and north, and governments further afield have increasingly deployed their own military within Syrian borders. As the year ends, there is some sign of progress in the form of a rare ceasefire in Homs, but also an increasingly combustible set of conditions that could spark a much broader international conflict if further political advances do not follow.

The international expediency of solving the Syrian crisis has increased following November’s Paris terrorist attacks and in light of UN Security Council Resolution 2259, which calls for greater action against ISIS. Increased French, and later British involvement in Syria, came not long after Russia had entered on the side of the regime of Bashar al-Assad, and added to the interests of the United States, Iran, Saudi Arabia, Turkey, and others.

The risks created by the increasing cast of characters was underlined by the November 24^th shooting down of a Russian warplane by Turkish fighters, who alleged that the aircraft crossed into Turkish territory. Russia disputed these claims and its rhetoric against Turkey has escalated sharply since. At an annual address to the Russian Federal Assembly on December 3^rd, President Vladimir Putin condemned the Turkish government, repeating accusations that it has been complicit in the ISIS oil trade and was supporting terrorism. Russia also enforced restrictions, both travel and economic, on Turkey last week.

The Paris attacks, meanwhile, have galvanized the French approach and could possibly precipitate a major shifting of alliances that could further complicate matters. President Francois Holland has partially amended the country’s NATO-directed strategy, which was to support Syrian rebels against Assad. France has now sought to create a broad-based coalition, including Russia, against ISIS and might even coordinate with Syrian regime forces to achieve this goal.

The new French approach has complicated the relationship with its NATO partners, who have been unanimous in their condemnation of the ISIS-claimed Paris violence but retained a clear policy that Assad cannot remain as Syrian leader. In addition, Russian action in Syria since September has largely focused on targeting moderate rebel groupings fighting Assad, the majority of whom are directly supported by NATO forces, including Turkey and the US.

The Syrian endgame remains largely unclear. While all states involved in the conflict are united in their opposition to ISIS, their policies on Assad and actions on the ground could not be further apart. The removal of the regime and ISIS, and offering support to moderate Sunnis is the primary goal for the West and Sunni states. For Russia, Iran and the Lebanon-based Hezbollah, maintaining the Assad regime is the priority along with crushing the Sunni rebellion and ISIS. Russia, in particular, is seeking to safeguard its Tartus naval facility and ensure that any post-conflict Syrian regime is aligned with its interests as it seeks to maintain and expand its regional influence in the Middle East. Iran and Hezbollah, meanwhile, require a friendly state in Syria to maintain Shiite Muslim interests, pressure Israel, and confront Saudi Arabia.

Since Paris and the Russia-Turkey incident, the stakes have dramatically increased. Rhetoric has spiked as most sides have attempted to position themselves to achieve their specific goals, without sparking a wider conflict. The UK Parliament recently passed a motion to increase air strikes in Syria against ISIS only, while French air strikes against the terrorist group in Syria have risen in frequency. Yet this campaign, as military experts and analysts point out, does not serve much purpose if it is not accompanied by a significant ground operation. It also does not provide a solution to NATO’s Assad problem. On the other hand, the risk of confrontation between major countries in Syria cannot be overstated should NATO deploy ground troops. It is this risk, and the reluctance of Western leadership to pursue a decisive solution, which is prolonging the conflict.

The US, as the chief military component of NATO, does not have the political inclination to deploy forces to a Muslim state again. President Obama’s established policy has been to avoid ground-based conflicts and rely on drone strikes to target opponents. The response to the 2013 and 2015 regime-led chemical attacks against rebel-held areas starkly underlined the administration’s lack of appetite for conflict. After stating that chemical attacks would constitute crossing a red line and thus lead to US military involvement, Obama failed to follow through, much to the chagrin of his Sunni and rebel allies. As he enters his final year, typically a period of limited political efficacy, increased US action should not be expected in Syria. This will in turn place limitations on France, the UK, and other NATO members.

The West’s reluctance to deploy ground forces does not decrease the risk of confrontation. Turkish involvement, for one, may increase in response to Russian attacks against its proxies in Syria, a number of recent ISIS attacks within its borders, and the risk of Kurdish forces in northern Syria expanding further. The last issue is a particular concern to Turkey, due to the presence of Kurdish rebels in its own restive southeastern provinces. While Turkey will not move against the US-supported Syrian Kurds militarily, it may seek other opportunities to ensure that they do not expand their territory or power. They can achieve this through increasing support for its Turkmen proxies, or by enforcing a buffer zone in northern Syria, something it has been threatening to implement in recent months. Should Turkey seek to involve itself in this type of manner, further confrontations with Russia will surely follow.

Israel remains another key consideration. From its perspective, both the survival of the Assad regime and the emergence of a Sunni-dominated government are poor outcomes. These longer-term considerations aside, the presence of Hezbollah, which it fought a month-long conflict with in 2006, and Iranian military forces near the Golan Heights would constitute grounds for intervention. Russian air support for pro-regime ground forces, including Hezbollah and Iran, in southern Syria has already occurred and further movements could lead to the crossing of Israel’s own red lines. As past precedent suggests, threats to Israeli territory, including the positioning of enemy forces near strategic locations or the deployment of armaments to Hezbollah, usually prompt a strong response. Should Israel seek to intervene, accidental confrontations between Russian and Israeli military forces could occur.

These risk of the Syrian conflict developing into an interstate one are very real, but are being managed for the time being. States from across the political spectrum continue to negotiate through the International Syria Support Group, whose last meeting was held in Vienna in mid-November. However, this process continues to exclude the various armed groups involved in the conflict, including the Syrian government, which seriously jeopardizes the achievement of any conclusion to the fight. Furthermore, some parties involved in the conflict also continue to meet separately. In December, moderate rebel groupings have met in Riyadh to formulate a common position ahead of possible talks with the Syrian regime. The talks excluded Kurdish armed groups. In the absence of inclusive talks and with the continuation of fighting, states will continue to pursue their own self interests in Syria. This alone will continue to serve to increase the risk of further confrontations at a minimum, and possibly a wider conflagration involving major international powers.