Cracking the Code: How one Telegram changed the course of the First World War

Sep 5, 2023 | READ

A fascinating account of how modern day code breaking evolved from the crucial successes made by British Naval Intelligence in the course of the First World War.

Again and again in history we can see moments when so much depends on something of seemingly small being discovered and developed. The reason for sharing this post is firstly to hint at some interesting historical associations, but still more to encourage us to keep praying for the Lord to be at work in everything surrounding the war in Ukraine.

We have shared many aspects for prayer concerning Russia’s war on Ukraine, but today I would like to approach it from a very different angle: a vital moment in history that came about as the result of arduous code breaking efforts nearly a hundred years ago in London by a bunch of eccentric linguists, intellectuals and puzzle solvers. The story is more than interesting in its own right – and, as I say, we can find ways to use the details to pray for similar efforts and breakthroughs to be made in our own time.

There were several episodes during the Second World War one can point to as having made a colossal difference to its duration and even to its outcome. The Battle of Britain springs to mind, as does the discovery much publicised in the recent program ‘War Games’ about how to ward off U boat attacks on the North Atlantic convoy routes, the cracking of the Enigma Code, the attack on Pearl Harbour that brought America into the war, the D-Day landings, the colossal efforts made to first develop and then to use the atomic bombs . . .

Sandwiched in the midst of that impressive list was the vital work of cryptology that was carried out at Bletchley Park – which, of course, led in turn to the development of modern day computers, and to the work of GCHQ, whose efforts we should most certainly be remembering in prayer. Not everybody, however, realises just how much the work of Bletchley Park was the direct successor, and indeed dependent on, the extraordinary achievements of a group of code-breakers in the First World War who made an outstanding contribution to its outcome.

This was carried out under the directorship of ‘Blinker’ Hall, a battleship captain who – providentially – had been reassigned to this work as a result of being unfit for active service. The work he did with what became known as Room 40 would ultimately be far more important than anything he could have achieved on the high seas. Their crucial work was featured in Episode 7 of the Cracking the Code series which has been shown on Sky television.

The need for effective codes for the military had become plain ever since the victoriously advancing German forces were thwarted in their advance on Paris in 1914 as the result of being in such a rush that they did not have time to encrypt their messages. As a result, the French were able to intercept their messages from the top of the Eiffel Tower, and to rush reinforcements to the places where the Germans had announced that they were going to direct their thrust. Paris was saved, but one can imagine that had it been taken then, things might have been very different.

From then on, both sides used a variety of codes to disguise their intentions. These unlikely ‘boffins’ in Room 40 proved their worth with their naval intelligence breakthroughs that influenced the battle of Dogger Bank in 1915, and the Battle of Jutland in the following year. By then, however, it was becoming clear that the British had lost so many men in battle, and were in such need of food and munitions, that they could not hope to win the war without more than the logistical support that America was providing, Britain desperately needed America to actually enter the war, but President Woodrow Wilson had been re-elected on a campaign promise not to enter it.

America even turned a blind eye when the liner the Lusitania was torpedoed with many dozens of Americans on board – and even hoped that the German Foreign Minister, Arthur Zimmerman, was a man they could look to, to bring about a peace in the European war. Asit turned out, he had plans only to expand the war.

In 1914, after war had been declared, a ship with cable busting facilities, set out from Dover (very much as Russian ships have been threatening to do these days) and destroyed German undersea cables. This meant that all overseas German communications to America had to go by a cable under the English channel, that we were able to intercept. Interpreting what we were intercepting of course was another matter. Britain was blessed with an outstanding code broker called Nigel de Grey, and when Germany sent a vital telegram first to Copenhagen and then across the Atlantic to Washington (for retransmission on to Mexico) all efforts were made to crack it.

In their dogged brilliance, de Grey and his team managed to decipher a crucial part of it: that from the beginning of February 1917, the Germans were going to unleash unrestricted submarine warfare around the British Isles. This was red hot material, because it meant that American ships would be sunk. The natural instinct was to warn America, but Britain faced a dilemma here; we didn’t want to admit that we were snooping on the Americans (just as in recent years they have been on their European and NATO partners!) and so Prime Minister Lloyd George initially advocated a wait and see policy.

The question of how to present this warning to Woodrow Wilson without admitting what we had been up to was quite brilliantly resolved. The answer was to focus on intercepting the German retransmission of its message from Washington to Mexico, thus keeping concealed the fact that we were tapping the cable under the English channel. This was achieved by bribing Post Office officials in Mexico in order to get hold of the telegram.

When they did so, however, they discovered that it had been sent in a different code! Fortunately, Room 40 found this code much easier to crack – and it revealed something quite astonishing – that the Germans were urging Mexico, undergirded by German finance, to launch a war on the United States in order to reclaim the states it had lost seventy years preciously: Texas, New Mexico and Arizona! It even spoke about making overtures to bring Japan into the conflict on their side.

(It reminds me of Putin’s open invitation to other nations to join Russia in its conflict with Ukraine. Its links with North Korea in this respect are particularly ominous).

In 1917, of course, this would have meant America becoming consumed with protecting itself, and directing all its resources in that direction, rather than helping in Europe. Even though, in reality, Mexico was in no position to win such a war, being embroiled at the time in a civil war, President Wilson felt he had to act now that German intentions had been made clear – especially when Foreign Minister Zimmerman admitted in the Reichstag to having sent the telegram. When the news was broken in America, it caused widespread shock. (US code brokers were credited with having achieved this breakthrough, much as they claimed the credit for a lot of the work that Bletchley Park achieved in the next war).

(A parallel to be prayerfully aware of today is that many Republicans are wanting America to send far fewer, if any, munitions to Ukraine, bas ed on the perceived need to build up the defence of its own country in case of hostilities with China.)

Right from the start in 1917, however, the involvement of American troops made a colossal difference in bringing the so-called Great War to a successful climax from an Allied point of view, for though the German generals wanted to fight on, the German forces were exhausted by the end of 1918.

Apart from praying for new military developments (which war always accelerates) Ukraine has such a need for more advanced military support – especially in the air; for diplomatic efforts; for code breaking, personal testimonies and leaked material that make a real difference in terms of being able to survive and to do more than survive.

Father, thank You for the many strategic moments there have been in history, that truly have changed its course for the better. We pray for many such at this time – and for success and anointing on teams of codebreakers who have such a vital role to play in keeping us safe from malicious hackers of all kinds.

Photo by Joshua Sortino on Unsplash


Welcome to the Blog