Note 286 — Chapter XXIX · FOREIGN RELATIONS

Communications between diplomats and their own governments are not usually sent by mail if the matters dealt with are of great importance. They are sent by special couriers or messengers. When diplomatic communications are sent by telegraph or cable they are transmitted in cipher, that is, in a secret code of words which no outsider can read. Nations occasionally get hold of one another’s diplomatic codes and decipher communications which they are not supposed to read. For example, the German government in the spring of 1917, before the United States declared war, sent a wireless message to its official representative in Mexico, telling him in substance that if America entered the war, he was to stir up Mexico against the United States by promising that when the war was over Mexico would be rewarded with some American territory. This message was in secret code; but the American officials caught it from the air, deciphered it, and at the appropriate time put the German government in an embarrassing situation by publishing the message in plain English to the whole world.