海角大神

Turkey鈥檚 shoot-down of a Russian fighter jet that it says strayed into its airspace from Syria Tuesday demonstrates why building a broad international coalition to destroy the self-proclaimed Islamic State is so difficult.

Well over a year after President Obama announced creation of a coalition of more than 50 countries designed to 鈥渄egrade and ultimately destroy鈥� IS, also known as ISIS, there still is no effective alliance of major powers.

Now French President Fran莽ois Hollande, who was at the White House Tuesday and will be in Russia Friday, has made building a coalition his goal in the wake of the Paris attacks. But the same challenge remains: The major players deeply mistrust one another鈥檚 intentions and visions for a post-Islamic State Syria.

鈥淚t was never going to be easy to build a coalition against ISIS, given the complicated relations and competing alliances around the Syrian conflict," says Barry Strauss, a military historian at Cornell University in Ithaca, N.Y.聽鈥淏ut clearly an event of this seriousness between Russia and Turkey will only make that effort more difficult.鈥澛�

Turkey and Russia exemplify the complex and often contradictory motives that Mr. Hollande will try to manage.聽

The anti-IS coalition聽supposedly has similar aims to Turkey鈥檚: the removal from power of Syrian President Bashar al-Assad as a key step toward reducing IS's allure for Syrian Sunnis. But it聽took months of sustained diplomatic effort for the聽United States to bring Turkey on board. Even now, the differences between the US and Turkey remain pronounced.

From the US perspective, perhaps the most effective fighters against IS have been Syrian and Iraqi Kurds 鈥� so much so that the US has sent special operations forces to the region to help them. But Turkey has a large Kurdish population and worries that empowering Kurds anywhere in the region might create trouble at home.聽

In fact,聽Turkey has been 鈥渇riendlier towards ISIS than Russia鈥� because of Turkey鈥檚 satisfaction with the setbacks that IS has dealt Syria鈥檚 Kurdish rebels.

Similarly, many countries in the region "find ISIS useful to have around and are in no rush to get rid of it" because it is virulently anti-Shiite, Professor Strauss notes. In that way, IS acts "as a counterbalance to Iran and the Shiite parties in the region."聽

For its part, Russia says it entered the Syrian conflict to defeat Syria鈥檚 鈥渢errorists,鈥� but analysts say its airstrikes in Syria have focused on Assad鈥檚 opponents. Only about a quarter have been against IS, experts say.

For those reasons, getting Turkey and Russia on the same page for destroying IS 鈥� a priority for neither 鈥� was always going to be difficult. After the Russian jet shoot-down, the task will be even harder when聽Hollande meets with Russian President Vladimir Putin Friday.

Mr. Putin called the downing of the Russian jet a 鈥渟tab in the back鈥� carried out by 鈥渁ccomplices of terrorists,鈥� and he warned that the perpetrators of the 鈥渃rime鈥� will face 鈥渟erious consequences.鈥�

Russia canceled Foreign Minister Sergey Lavrov's visit to Turkey Wednesday, while NATO called an emergency meeting of alliance ambassadors Tuesday afternoon. Tuesday鈥檚 incident was the first shoot-down of a Russian aircraft by a NATO country since the 1950s, officials said.

Russia insists the fighter jet did not stray outside Syria, while Turkish officials said the jet was warned 10 times to turn back from its trajectory into Turkish airspace. Mr. Obama called on Russia, Turkey, and NATO countries to 鈥渄iscourage any escalation,鈥� but also asserted that 鈥淭urkey, like every country, has the right to defend its territory and its airspace.鈥�

Russia is likely to look at the aftermath of the incident as validation that all groups arrayed against Assad are terrorists.聽A video released following the shoot-down shows Syrian Turkmen rebels claiming to have shot dead two Russian pilots as they parachuted to the ground.

A separate incident further illustrates the聽difficulty of building a united anti-IS coalition that includes Russia.聽A group of Syrian rebels armed by the US claims to have damaged a Russian military helicopter, forcing it to make an emergency landing in Syrian government-held territory.

Yet Strauss says perhaps聽the more formidable impediment to an effective coalition is the widespread ambiguity in the region toward the Islamic State.

The region鈥檚 Sunni powers 鈥渕ay worry about ISIS in the long term, but to some extent they see its usefulness in the short term,鈥� he says. That calculation does not fit with Western powers that 鈥� now more than ever 鈥撀爓ant to see IS鈥檚 demise "sooner rather than later."