Page:The Practice of Diplomacy - Callières - Whyte - 1919.djvu/172

 them. And since a true judgment of events in one country will often depend upon what is happening in others, a diplomatist in foreign parts will ever keep in touch with his colleagues in other foreign countries, so that he may be informed of the course of events elsewhere. This co-operation between ambassadors abroad is one of the most useful features in diplomacy.

As secrecy is the very soul of diplomacy, the art of writing letters in cipher has been invented in order to disguise the written message, but unless the cipher is unusually clever the industry of men, whose wits are sharpened by necessity and by self-interest, will not fail to discover the key to it. Indeed, to such a pitch has this been brought that there are now men who are known as professional decipherers, though in all probability, as I believe, their reputation rests largely upon the ineptitude of poor ciphers rather than upon their discovery of a good cipher. For as a matter of fact experience shows that a well-made and well-guarded cipher is practically undiscoverable except by some betrayal, that is to say, that the wits even of the cleverest student of ciphers will fail to pierce its secret unless aided by corruption. It is therefore the duty of the ambassador, having satisfied himself that the ciphers of his government are adroitly made, to take all means for their due protection, and especially