At least three Syrian mortar shells landed in Turkish Akçakale near the southern border on Wednesday, killing five people and injuring eight. Will this be the tipping point for a Western intervention?

Turkish prime minister Recep Tayyip Erdoğan almost immediately vowed, “These provacations against the safety of Turkey will not remain unanswered” and announced that targets in Syria had been bombed in retaliation.

The incident comes after a Turkish warplane was brought down by Syrian air defenses on the Mediterranean coast in June. Erdoğan said at the time that further Syrian violations would be met with force and invoked Article 4 of the North Atlantic Treaty to call a meeting of NATO ambassadors. Secretary General Anders Fogh Rasmussen said that Article 5, under which an attack against one member can be considered an attack on all, was not discussed.

Will it be this time? All of Western nations’ apprehensions about intervention still stand and even if Article 5 is invoked, it doesn’t necessarily commit allied nations to war. If the situation escalates further, however, and NATO does decide to intervene, what would it look like?

The first phase of an attack would likely involve the disrupting of Syrian air defenses. Air and missile strikes could be launched from airfields in Turkey and a carrier strike group in the Mediterranean Sea.

As June’s downing of the Turkish reconnaissance jet demonstrated, Syria’s air defense capabilities are not to be underestimated. General Martin Dempsey, the chairman of the American Joint Chiefs of Staff, pointed out in February of this year that the country has “a very sophisticated, integrated air defense system.”

Syria has invested in upgrading its 1970s era air defense capabilities since the Israeli attack on a suspected nuclear facility outside the eastern city of Deir ez-Zor in 2007, wrote John Reed in Foreign Policy in July, “buying at least 36 SA-22 mobile air defense systems from Russia.”

The SA-22 comes equipped with its own target acquisition and tracking radars, along with twelve medium range missiles. This system might have been used to shoot down the Turkish plane.

Syria has also ordered SA-10 (known as S-300 in Russia) long range, high altitude surface to air missiles that are among the most advanced in the world. Russia canceled a sale of these very weapons to Iran in October 2010 after weapons sanctions were enacted against Tehran.

Syria’s air defenses will pose a challenge to a NATO offensive and casualties should not be ruled out. The country also boasts a sizable air force. Many planes are of vintage Soviet make, the most advanced being the MiG-29 Fulcrum which entered service in 1983. It was designed to be an air superiority jet against the American F-15 and F-16 fighters but did not perform well, in Iraqi and Yugoslavian service, against its Western counterparts.

The USS Dwight D. Eisenhower aircraft carrier, which is currently on deployment in the Arabian Sea, carries up to ninety aircraft. The French Charles de Gaulle can carry up to forty. British fighters could fly out of Cyprus but the Turks would have to play a key role to augment the allied force.

The Turkish Air Force is equipped with 240 F-16 fighter jets and almost three hundred older F-4s and F-5s.

Once NATO has achieved aerial superiority, which should also prevent Syria from deploying helicopter gunships against the invasion army, mainly American and Turkish armor and mechanized divisions would cross the border into Syria, perhaps supported by a marine landing in the northwest, the Alawite heartland where the Russian naval facility at Tartus is situated.

The Syrian army operates several thousands of tanks, the majority of which are over fifty years old. The most potent battle tank in the Syrian arsenal is the 1970s Soviet-made T-72. “For all this tank was feared when it was first deployed in the late 1970s,” writes Reed, “the ones Iraq fielded during Operation Desert Storm were soundly defeated by American M1A1 Abrams tanks.”

Like Syria, Turkey operates hundreds of 1950s and 1960s era battle tanks. Its most modern system is the 1980s German-made Leopard 2A4 which is superior to the T-72. More than three hundred are in Turkish service.

The ground battle could very well resemble the 2003 invasion of Iraq which saw just three weeks of major combat operations and 172 killed on the side of the coalition. Of course, some 265,000 Western forces were deployed in the invasion but they did not face an army that had been weakened by eighteen months of civil war, nor did they have strong local support except from Kurdish militias in the north. NATO would be unlikely to launch an invasion unless it was coordinated with Free Syrian Army rebels on the ground.

NATO casualties could mount considerably if Assad deploys chemical weapons. Syria is estimated to possess hundreds of tons of mustard gas and large stockpiles of sarin gas, possibly VX, both of which are nerve agents. These weapons can be fired from even antiquated artillery as well aircraft and missiles.