Will the tense situation between Syria and Turkey escalate into full-fledged war? This possibility is looking increasingly likely after the most recent conflagration on their common border.Though it was unclear whether forces loyal to President Bashar Assad were responsible for mortar fire from Syria that killed five Turkish civilians, Ankara responded quickly and decisively on Wednesday. Turkey’s military hit targets inside Syria, reportedly killing Syrian soldiers.This is not the first time the two countries have come into direct conflict.On June 22, the Syrian military shot down a Turkish RF-4 Phantom reconnaissance aircraft together with two pilots. Turkey’s Prime Minister Recep Tayyip Erdogan made a few bellicose declarations, including calling the Assad regime a “clear and present danger.”The rules of engagement for the Turkish armed forces were changed and expanded. In the future, any military element approaching Turkish borders from the Syrian side would be considered a direct military threat. Still, at the time Turkish military forces refrained from openly retaliating. This time they did not.Under Erdogan’s leadership, Ankara has been providing support to the Syrian opposition forces almost from the very beginning of the uprising against Assad that began 18 months ago.Turkey has emerged as a regional hub of anti-Assad activity. In the past year, the opposition Syrian National Council has established an office in Istanbul, with a section dedicated to military coordination. The nominal leadership of the rebel Free Syrian Army, along with an estimated 33,000 Syrians who fled the spiraling violence inside their country, are based in 10 Turkish camps in the border region.There are a number of reasons for Ankara’s decision to turn against the Assad regime, after several years during which the old rivalry between the countries seemed to be weakening and relations improved. (In 2008, ties between Damascus and Ankara were so good that Turkey served as a facilitator between Israel and Syria to enter negotiations over the fate of the Golan Heights.) Ankara’s turn against Damascus has more to do with Iran than with Syria. Turkey’s leaders, faced with the strong ties that exist between Syria and Iran, realized the futility of continuing to try to woo the Alawite regime away from the Shi’ite Islamic Republic.Replacing Assad with a Sunni regime in Damascus would help counter Iran’s Shi’ite expansionism in the region. Iran has succeeded in forging strong ties with Iraq’s political leadership that is dominated by pro- Tehran elements. And in Lebanon, Hezbollah, with its own standing army, has succeeded in consolidating its political hegemony.Assad has also been increasing his support for the PKK, a terrorist organization fighting Turkey for an autonomous Kurdistan that would be carved out of Turkish territory. Finally, Turkey would like to see a quick end to the civil war in Syria in order to prevent a major refugee crisis. Thousands of Syrians have already fled across the border to Turkey to escape the brutality of Assad’s forces.If the violence continues, a full-blown humanitarian crisis could be created in Turkey. To prevent such a scenario, Ankara might be persuaded to use force to secure a buffer zone inside Syrian territory. And this could lead to open fighting between Syrian and Turkish forces.It is still too early to determine whether the situation on the Turkish-Syrian border will escalate. And it is difficult to know who to root for. While it would be morally reprehensible to back Assad’s ruthless regime, the alternative – the rise of a Syrian version of the Muslim Brotherhood, followed by the wholesale slaughter of the hated Alawite minority (and perhaps of other minorities such as Druse and Kurds who remained loyal to Assad) – hardly promises to be an improvement.From Israel’s point of view, regime change in Syria and a warming of ties with Turkey would be welcome developments.Israel is closely monitoring the situation in both countries.But when it comes to changes in the Arab world, as we learned in the Gaza Strip and then with the so-called Arab Spring, one must be careful what one hopes for.