Read the excerpt from The Dark Game.
On January 16, 1917, in a clear attempt to convince the
Mexican government to help Germany in the war, Arthur
Zimmermann, the German foreign secretary, sent a
telegram to Count von Bernstorff, the German
ambassador in Washington. The foreign secretary
wanted to be certain that this message reached von
Bernstorff, so he made arrangements for it to be carried
aboard a U-boat to Sweden and from there to
Washington through diplomatic channels.
As luck would have it, the departure of the sub was
delayed. Impatient, Zimmermann turned to his second
option: sending the message to his ambassador through
the U.S. State Department. Although Wilson considered
the United States to be