
GCHQ / Cyber & technology · History
Germany Offered Mexico Three American States. British Codebreakers Read the Offer.
The Zimmermann Telegram became a diplomatic weapon in 1917. London first had to hide how it had acquired it.
SPY REGISTER / REPORTING & ANALYSIS
Intelligence reporting from Mexico.

The Zimmermann Telegram became a diplomatic weapon in 1917. London first had to hide how it had acquired it.