Air Services Agreement Case France v US

By 1946 bilateral agreement France and US provided for civil air flights between their two countries. Pan American Airlines announced a service via London with a change of gauge, France alleged that such change was a violation of the agreement and she did not allow disembark of passengers in Paris in 3 May 1978. On 4 May 1978 US proposed the disputed to be referred to arbitration, a compromis was signed on July. Meanwhile, US issued an order prohibiting flights by French designated carriers to the US west coast from Paris via Montreal. Following the compromis US ban was not implemented. The AT decided that under agreement 1946 US carriers were entitled to operate with a change of gauge in London. In reference to the question whether US was entitled to take the action that it took immediately prior the signing of the compromis the AT said:

(81) if a situation arises which, in one state’s view, result in the violation of an international obligation by another state, the first state is entitled, within the limits set by the general rules of international law pertaining to the use of armed force, to affirm its rights through ‘countermeasures’ (83) all countermeasures must, in the first instance, have some degree of equivalence with the alleged breach; this is a well-known rule… judging of ‘proportionality’ of countermeasures is not an easy task and can at best be accomplished by approximation. It is essential not only to take into account the injuries suffered by the companies, but also the importance of the questions of principle arising from the alleged breach …the measures taken by the US do not appear to be clearly disproportionate when compared to [the action] taken by France