"The controls at the border are what is causing Mr Caruana to be dissatisfied with the situation and with the British Government itself. The frontier controls are what is causing Mr Caruana to look for alternatives and formulas to roach understanding with Spain and they are what is causing Mr Caruana to know that the Spanish Government is not content with the situation and that he must change his attitude if he wants those controls to take a less restrictive form. Any step to lift or soften those controls without obtaining anything in exchange would purely and simply weaken Spain's position and would reward Mr Caruana in his efforts not to implement the airport agreement or to accept other formulas for cooperation which have been proposed to him".