It gives me great pleasure to write a foreword to :1r. Sen's excellent book, and for two reasons in particular. In the first place, in producing it, Mr. Sen has done something vvhich I have long felt needed to be done, and which I at one time had am­ bitions to do myself. Vhen, over thirty years ago, and after some years of practice at the Bar, I first entered the legal side of the British Foreign Service, I had not been working for long in the Foreign Office before I conceived the idea of writing - or at any rate compiling - a book to which (in my own mind) I gave the title of "A ~fanual of Foreign Office Law. " This work, had I ever produced it in the form in which I visualised it, could probably not have been published con­ sistently with the requirements of official discretion. But this did not worry me as I was only contemplating something for private circulation within the Service and in Government circles. :Mr. Sen's aim has been broader and more public-spirited than mine was; but its basis is essentially the same.