On this date in 1915, a brace of German zeppelins engaged in the first serious aerial bombardment of a civilian target, dropping a few dozen bombs out of the night skies onto English towns. Unfortunately for the Jerries, they never really got the knack of strategic bombing, but the British seemed to think it was a swell idea. They proved to be enthusiastic pupils and less than thirty years later were burning German cities to the ground at pretty much a one-per-night clip.
Stumped for an encore, it took two years of hard work by the Kaiser's foreign secretary to come up with a more boneheaded maneuver: In January of 1917 Secretary Zimmerman, showing a complete misapprehension of strategic realities in the Western hemisphere, sent a telegram to Mexico, proposing an alliance against the still-neutral United States. Needless to say, when the British (who had been tapping everybody's phones) decrypted the document, they couldn't wait to show Wilson what the Boche had been saying about us behind our backs.