The Economic Times

The US stayed out of World War I for three years. Then a secret German telegram in 1917 changed everything

During World War I, a clandestine German telegram sparked a controversial proposal for Mexico to launch an attack on the United States. British intelligence successfully intercepted and decoded this crucial message, revealing offers to regain lost territories. The confirmation of the telegram's authenticity by Germany swayed public opinion in America dramatically, alongside escalating submarine warfare, ultimately leading the United States to declare war against Germany in April 1917.