State Sovereignty and Its Limits
The sovereignty principle
Article 1 of the Chicago Convention is the bedrock: each State has complete and exclusive sovereignty over the airspace above its territory, including territorial waters. Territory for this purpose includes land areas and adjacent waters under the State's sovereignty. Sovereignty means a State may admit, exclude, or condition entry by foreign aircraft, and may designate prohibited, restricted, or danger areas under Article 9.
The corollary rules
Because sovereignty is exclusive, foreign aircraft need permission to enter. Article 5 gives a limited permission for non-scheduled flights and non-traffic stops; Article 6 requires permission for scheduled services. Cabotage (Article 7) is the carriage of traffic between two points within the same State by a foreign carrier; States may reserve it, and the Convention does not require them to grant it. Article 3 excludes State aircraft (military, customs, police) from the Convention's operation, though States must have regard to the safety of civil aircraft.
Territorial sea and straits
Airspace over the territorial sea is sovereign, so overflight needs permission; the right of innocent passage applies to ships, not aircraft. Archipelagic sea lanes and straits used for international navigation have their own regimes, but candidates should not assume a general right of overflight without agreement.
Traps
A frequent distractor says the high seas are sovereign or that a State may not restrict flight over its own territory. Another confuses cabotage with the eighth or ninth freedom, or claims that State aircraft are bound by Annex 2. Note that a State may prohibit flight over specific zones but must not discriminate against foreign aircraft.
Rule of thumb
If the stem asks whether a foreign carrier may fly domestically without permission, the answer is no: cabotage is reserved unless granted by agreement.