How did the invention of the telegraph affect World War One and Two ? Which country made up secret codes?

The telegraph had been invented in the early part of the
19th century and became the first electromechanical device in widespread use for
communication. During World War I, the British intercepted an encoded telegraph
transmission from the German Foreign Secretary, Alfred Zimmermann (1864-1940) to the
German Ambassador in Mexico City.  It proposed that should the United States enter the
war, Germany would aid Mexico in reclaiming the southwestern United States. When the
contents of the telegraph transmission was made public, isolationist sentiment in the US
waned in favor of war with Germany.

In January, 1923,
Germany fell behind in reparation payments to the Allies, notably in a promised delivery
of telegraph poles to France. This failure prompted France to occupy the Rhineland.
 (The "Ruhr Crisis") which weakened the German Weimar Republic, and eased the way for
Nazism in the 1930's, and world war in the
1940's.

Zimmermann