18 Ways World War I Directly Shaped The Way We Live Now

It was in WWI that "technology became an essential element in the art of war," to quote Guillermo Altares of El País. Submarines, aerial bombardment, armored tanks, toxic gas attacks, barbed wire - all were either invented or revolutionized during the Great War.

It was also the first time technology was such an overwhelmingly destructive force, with poison gas alone capable of wiping out thousands at a time. The Germans even had so-called "blue cross" shells containing diphenylchlorarsine, which made victims sneeze violently. They called these shells "mask breakers."

Historian Jay Winter argues that WWI "discredited the concept of glory" and exposed the idea that it was noble to perish for one's country as an "old lie." Winter claims that the "propaganda" literature and painting of war was "cleaned away" by artists and poets following WWI because "millions of men slaughtered deserved more than elevated prose; they deserved the unadulterated truth."

This truth came to light in the "nonsense verse of the Dada movement and in the nightmare paintings of the surrealists," who "denounced the obscenities" of armed conflict. Winter also notes that soldiers writing popular memoirs helped expose the realities of WWI to millions back at home.

The British developed a knack for code-breaking during WWI, particularly with encrypted German radio transmissions. These advancements later led to now-famous intelligence-gathering operations such as MI-8, GCHQ, and the NSA in the US.

The most famous bit of code-breaking during WWI was the so-called Zimmermann telegram: German Foreign Minister Arthur Zimmermann received an encrypted telegram describing plans to attack US shipping lanes to the UK. The telegram also mentioned Germany's desire to ally with Mexico and have the Mexican army attack US territory. This decoded telegram led the US to declare war on Germany in April 1917. 

Post-traumatic stress disorder (PTSD) wasn't formally recognized until 1980, but during and after WWI, doctors began to understand and diagnose the psychological impacts of conflict in a new way, which laid the groundwork for our modern understanding. During WWI, some medics thought the physical impact of explosions caused the "war neurosis" so many soldiers were experiencing (also known as shell shock).

We now better understand - thanks largely to the efforts of doctors and scientists during WWI - that the emotional stressors of war are to blame for the symptoms shown by thousands of soldiers coming home from the battlefield. Because so many WWI-era soldiers (80,000 British soldiers, by one estimate) were experiencing these symptoms in the safe confines of their homes, scientists and doctors began looking for answers.

Prior to WWI, the US was primarily a debtor country. That changed with WWI in a big way: Hugh Rockoff of Rutgers University says the "turnaround was dramatic." The US emerged from the Great War as net creditors "to the tune of $6.4 billion."

This later led to New York being considered the de facto financial capital of the world, a spot previously held by London. Rockoff also says that WWI taught the federal government how to play "an important positive role in the economy," a lesson it put to good use in the Great Depression.

Before WWI, British Petroleum (BP) was known as Anglo-Persian Oil Co. At the time, the company wasn't very successful; in fact, if it wasn't for Winston Churchill's decision to build faster warships that ran on oil instead of coal, BP may have gone bankrupt.

Instead, the oil industry flourished, thanks largely to the WWI effort. Oil became incredibly important to keeping the newly mechanized style of warfare going, and protecting oil supplies became a huge part of the strategy of warfare - just as it is today.