Final answer:
The main difference is that the International Air Services Transit Agreement grants the first and second air freedoms, while the International Air Transport Agreement grants these and adds three more, for a total of five freedoms of air which support international civil aviation and trade.
Step-by-step explanation:
The difference between the International Air Services Transit Agreement and the International Air Transport Agreement lies in the freedoms of air that each agreement grants. The International Air Services Transit Agreement, also known as the Two Freedoms Agreement, allows for the first and second freedoms of air, which are the right to fly over a foreign country without landing and the right to refuel or carry out maintenance in a foreign country without embarking or disembarking passengers or cargo.
On the other hand, the International Air Transport Agreement, often referred to as the Five Freedoms Agreement, includes the rights granted by the International Air Services Transit Agreement and adds three more freedoms. These additional freedoms are the right to put down passengers in the territory of the treaty-signing country, the right to pick up passengers in the territory of the treaty-signing country to another country, and the right to carry passengers or cargo between two foreign countries during flights that originate or end in one's own country.
These agreements are significant in the context of the development of a civil airline infrastructure, as well as in the broader framework of international trade policy. Airports with efficient terminals are crucial for commercial passenger air traffic, influencing international trade and negotiation of various trade policy treaties, like the GATT and WTO, which have shaped global trade practices and tariff policies.