Tuesday's downing of a Russian aircraft by the Turkish Air Force has added a new dimension to the complicated conflict in Syria and marks one of the most high-profile incidents between Russia and a NATO member for decades. Airspace violations have become increasingly common in recent years with the majority of encounters between NATO and Russian aircraft proving peaceful and routine, something that may change in light of events on Tuesday.Interestingly, airspace violations have actually proven a huge flashpoint between two NATO countries for decades. Turkey and Greece dispute the sovereignty of islands in the Aegean, as well as the delimitation of territorial waters and national airspace. The latter resulted in frequent confrontations between the air forces of both countries, confrontations that have sometimes turned aggressive. As Greece struggled with its financial problems over the past three years, Turkey increased its violations of Greek-claimed airspace in the Aegean. In 2014, there were 2,244 intrustions alone according to the Greek military and by October of this year, military authorities claimed 1,443 airspace violations.