How did Germany try to use Mexico to keep the US out of WW1?

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1. Playing on distrust and fear

When war broke out in 1914, America wanted little to do with what had begun as a European conflict. Its leaders had problems of their own, among which was a tense and sometimes deadly dispute with Mexico.

Almost half of Mexico's territory had been taken by the United States in the late 19th Century. As World War One dragged on, Germany offered them an opportunity to get it back. This is the story of how that attempt went spectacularly wrong.

2. A brief history of a border

1521-1535 Mesoamerican civilisation is thought to have existed in Central America since around 21,000 BC. Conquistador Hernán Cortés conquers the Aztec Empire and New Spain is created.

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1819 The Adams-Onis Treaty establishes the border between New Spain and the United States. Two years later, Mexico wins independence from Spain and becomes a republic.


1835-1845 American settlers in Texas declare independence from Mexico, leading to Texan independence and appeals to be annexed by the United States. Wary of admitting a new slave state, the US doesn’t admit Texas into the Union until 1845.

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1846-1848 Mexico refuses to recognise the US annexation of Texas. America declares war after skirmishes along the border. Mexico is defeated and signs the Treaty of Guadalupe Hidalgo, turning over 55% of its land, including California and New Mexico.

1884 A treaty specifies that the Rio Grande river marks the new border between the US and Mexico.

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1910 The Mexican Revolution begins. Native Mexicans move north in their thousands to escape the conflict and economic hardship. As the economy booms in the American West, many are employed in mining, agriculture and railroad construction.

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1914 Revolutionary violence leads America to garrison its border towns. President Wilson orders the occupation of Veracruz after Mexican authorities hold US Marines in Tampico. Diplomatic relations between the countries are increasingly strained.

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1916 Mexican revolutionary General Pancho Villa raids the town of Columbus, New Mexico. In retaliation, 10,000 US troops are sent into Mexican territory. The Germans spot an opportunity to seize on Mexican resentment.

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3. Germany's deadly diplomacy

Before intervening in the Americas, Germany had already attempted to play allies off against their enemies.

4. Make war together, make peace together

In 1917 Germany wanted Mexico's help to stop America entering the war against them.

5. America joins the war

The Zimmerman Telegram is often credited with bringing America into World War One in the spring of 1917. In fact, America's involvement was probably inevitable by then.

America had done its best to stay neutral as the world descended into conflict. While he never used the phrase himself, President Woodrow Wilson was re-elected for a second term in office under the slogan ‘the man who kept us out of the war’. Yet although America had not committed troops, her allegiances were becoming clear.

America had begun the war trading with countries on both sides of the conflict. However, British blockades had made it harder for America to do business with Germany and the other Central Powers. At the same time, America’s exports to Britain and France grew, while Wall Street banks loaned large amounts of cash to the Allies, often to buy American goods. American businesses had an increasing stake in the fate of the allies.

Tipping point

Earlier in the war, German U-boats had sunk a number of American ships bound for Britain. In particular, high profile events such as the sinking of the Lusitania passenger liner in 1915 made Americans wary of German power. Only a pledge from Germany to stop attacking passenger ships had prevented America from severing diplomatic relations in 1916.

In 1917 Germany resumed unrestricted submarine warfare, and this – among other reasons – acted as a tipping point. American ships were being sunk, and American civilians were dying on British ships.

Just as importantly, Germany had broken its promises. American honour and credibility were at stake. When Woodrow Wilson went to congress to ask for permission to take America to war, he used Germany’s attempts to entice Mexico into an alliance as an argument for action. But the reality is that America would probably have gone to war even without Germany’s diplomatic blunder.

6. The border today

Today the border between the US and Mexico is the most frequently crossed international border in the world. However, relationships between the two countries remain strained.

As the 20th century progressed, it became harder and harder for people to move back and forth between the two countries. Restrictions imposed during the First World War were tightened during the Great Depression of the 1930s. As the economy foundered, immigrants who had lived in the United States for decades were repatriated .

A clash of cultures

While economic fears have stoked distrust between the US and Mexico, more tension has stemmed from the fact that the countries are culturally different. The Mexican Revolution of the 1910s left the country a less religious and more left-wing state. Many Americans fear that immigrants will change the cultural, linguistic and political landscape of the nation.

Such concerns are encapsulated by campaigns to make English the official language of the United States.

A growing border wall

Since the Clinton administration of 1993-2001, the American government has overseen the construction of sections of an imposing wall, in addition to an increase in patrols along key parts of the border. While these policies have gone some way to reducing illegal crossings, it has not been possible to prevent illegal immigration into the United States.

7. How WW1 changed the US-Mexico border

World War One saw many changes along the US Mexican border. But which of these changes occurred between 1914 and 1918?

First border patrols

Today over 21,000 agents patrol the border between the US and Mexico.

Before World War One

First border patrols

Introduced in 1904

Mounted watchmen first patrolled the border in 1904. Until 1915, a maximum of 75 men patrolled the entire border.

First US passports

Passports offer protection for nationals abroad, and can be required to enter or leave a country.

Before World War One

First US passports

Introduced in 1775

The US introduced temporary passport requirements during the civil war and World War One. They were not required again until 1941.

Literacy test for immigrants

The first literacy test required all immigrants over the age of 16 to read between 30 and 40 words.

During World War One

Literacy test for immigrants

Introduced in 1917

Literacy tests were introduced along with a rise in ‘head tax’ for people crossing the border. This prompted more immigrants to cross the border illegally.

Joint US-Mexico drugs strategy

Today, most illegal drugs enter America across the US Mexico border.

After World War One

Joint US-Mexico drugs strategy

Introduced in 1998

Despite the Brownsville agreement between America and Mexico, organised drug cartels still cause major problems for border enforcement.