The media attention in these days is focused on the alleged incursions of NATO aerial space (from Poland to the Baltic countries) by unauthorized drones: last night the Danish airport of Aalborg was closed again after the sighting of suspicious drones, even if no confirmation has yet arrived from the authorities on their sovereignty.
In a scenario like the current one, where we often hear improperly talk about “third world war”, we try to understand a little better than what a country’s airspace is and what its violation can involve. The Chicago convention of 1944 establishes that each state has full and exclusive sovereignty on the air space above its territory (which includes the mainland and territorial waters, which extend up to 12 marine miles from the coast). In vertical, however, things are more complicated, because there is no international agreement that specifies the limit: by convention, the imaginary line of Kámán (100 km from the ground) is adopted, to distinguish the airspace from the extra-atmospheric one.
In any case, the violation of the airspace of a state implies the violation of its borders: in the case of NATO there is a shared mission of Air Policing To monitor and intervene immediately in the case of trespassing.
How to calculate the airspace of a state: the map of Italy
As mentioned, a state exercises its sovereignty (and therefore its control) within its territory. The latter includes land, territorial waters (up to 12 marine miles from the coasts) and also heaven, with the airspace that is in fact a part of the state. The problem is that, if from a terrestrial point of view, it is relatively simple to trace boundaries (also thanks to the presence of physical borders or natural elements such as rivers or mountainous chains), in the case of aerial space this task is not as easy, so much so that these boundaries can often be defined as “invisible”.
In practice, the Chicago convention provides that, from a horizontal point of view, the airspace of a state includes “the terrestrial regions and the adjacent territorial waters” up to 12 marine miles, as can be seen below with the map of Italy.
But if from a horizontal point of view, the outline is quite simple (all the mainland plus the 12 marine miles from the coasts), from a vertical point of view the distinction becomes more complex, given that the Chicago convention does not establish anything specific. By convention, the Kármán line is taken as a reference, i.e. the imaginary border that marks the limit between the Earth’s atmosphere and the outdoor space, located about 100 kilometers above the sea level: this border, in fact, marks the beginning of the extra-atmospheric space, which is considered res communis omnium On the basis of the Treaty on the 1967 extra-atmospheric space. To understand, beyond the atmosphere, no state can exclusively exercise its sovereignty, exactly as it happens in the case of international waters.
The problem, however, is that the division established by the Kármán line is not recognized by the Chicago convention or by the Treaty on the extra-atmospheric space and, consequently, does not have a binding (and therefore mandatory) value for the states.
What happens if an unauthorized aircraft is intercepted in NATO aerial space
In short, although being outlined by “invisible” boundaries, the airspace remains a territory of the state and, as such, it is inviolable. Precisely for this reason, from a legal point of view, entering into the airspace of another state without its authorization implies an invasion of its borders and, consequently, violation of international law.
In practice, when an unauthorized aircraft is intercepted in aerial space, there are standard procedures established by ICAO itself, the international organization of civil aviation that was created with the entry into force of the Chicago Convention.
Specifically, after being intercepted, the aircraft is primarily forced to respond to visual and radio signals: in case of failure to respond, the support of an airplane immediately starts to try to better understand the dynamics of the facts: it could in fact be a terrorist attack, but also a aircraft that is no longer able to communicate due to a technical malfunction.
At that point, the intruder aircraft can be escorted on the ground, forced to a obligatory landing or forced to be accompanied outside that air space, and then be sanctioned for violation of the boundaries of a state.
In the case of NATO, since it is a military alliance (which also includes Italy), the controls are even more strengthened: for the countries of the Atlantic alliance, in fact, the system of Air Policinga permanent control mission (carried out collectively) which involves the continuous presence – 24 hours a day, 365 days a year – of combat planes and crews, ready to react immediately in the case of possible violations of the airspace.
There Air Policing It takes place using the Integrated Air Defense and Missilistic System of NATO (NIAMDS) and is supervised by the Alleato Air Command (Aircom) thanks to two aerial operational centers: one in Torrejón, Spain, which covers the air space south of the Alps, and one in Uedem, in Germany that covers the North.
The mission of Aerial police NATO has been active since the 1950s, but was integrated in 2004 with a mission dedicated to the Baltic countries (Baltic Air Policing), under the control of Italy until the end of 2025.
