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In January 1917, Germany's foreign secretary, Arthur Zimmermann, secretly cabled Mexico an offer: if the United States entered the war, join Germany against it and win back Texas, New Mexico and Arizona. British codebreakers decrypted it, and its publication helped bring America into the First World War.

Germany, January 1917

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The story behind the card

The codebreakers worked in Room 40, the British Admiralty's secret decoding office in London. Revealing the message was delicate: the telegram had travelled partly over American diplomatic cables, and Britain did not want the United States to know it was reading them. The answer came from Mexico, where the German embassy in Washington had forwarded the text by commercial telegraph in an older code. A British agent bribed a telegraph-office employee for a copy, so Britain could say it had obtained the message in Mexico and hide how much it could really read. The text appeared in American newspapers on 1 March 1917. Many suspected a British forgery until Zimmermann himself admitted two days later that it was genuine. Congress declared war on Germany on 6 April.

Türkçe oku
Almanya Dışişleri Bakanı Arthur Zimmermann, Ocak 1917'de Meksika'ya gizli bir telgraf gönderdi: ABD savaşa girerse Meksika Almanya'nın yanında yer alacak, karşılığında Teksas, New Mexico ve Arizona'yı geri alacaktı. İngiliz şifre çözücüler telgrafı okudu; yayımlanması ABD'nin Birinci Dünya Savaşı'na girmesinde etkili oldu.
Almanya, Ocak 1917

Şifreyi, İngiliz Amiralliği'nin Londra'daki gizli şifre çözme birimi Room 40 kırmıştı. Mesajı açıklamak ise hassas bir işti: Telgraf yolunun bir bölümünü Amerikan diplomatik hatları üzerinden geçmişti ve İngiltere, bu hatları dinlediğini ABD'nin öğrenmesini istemiyordu. Çözüm Meksika'dan geldi. Almanya'nın Washington Büyükelçiliği metni Meksika'ya sıradan bir ticari telgrafla ve daha eski bir şifreyle iletmişti. Bir İngiliz ajanı, telgraf şirketindeki bir çalışana rüşvet verip bu metnin bir kopyasını aldı. Böylece İngiltere mesajı Meksika'da ele geçirdiğini söyleyebildi ve gerçekte ne kadarını okuyabildiğini gizledi. Metin 1 Mart 1917'de Amerikan gazetelerinde yayımlandı. Pek çok kişi bunun bir İngiliz uydurması olduğunu düşündü, ta ki iki gün sonra Zimmermann'ın kendisi telgrafın gerçek olduğunu kabul edene dek. ABD Kongresi 6 Nisan'da Almanya'ya savaş ilan etti.

Sources and further reading

Background reading: Zimmermann Telegram
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