21 JANUARY 1955, Page 5

to UNO, has expressed confidence that the eleven American airmen

will be freedi-and Mr. Foster Dulles has been at pains to explain that the invasion of Yi Kiang Shan is anything but a casus belli. There must be some justification for all this optimism and it is not lessened by the scarcely surprising fact that Senator Knowland finds it impossible to throw himself wholeheartedly into the festive atmosphere. For all that is said about everyone's determination not to achieve the release of the prisoners by means of a bargain, Mr. Hammarskjold must have been exploring the possibilities of a bargain if his visit has been any use at all. If he succeeds. the old point that the United Nations is at its best when used as an instrument of negotiation, rather than as a judge or a policeman, will be reinforced.