The battle against extreme weather set off actual war in ancient times

Sometimes, a storm that is already brewing can start a greater storm.

Horrible weather could mean the enemy storming into your city. New research on the Samguk Sagi, which are the oldest surviving records of Korean history, has revealed that people were more than twice as likely to fight each other if they were hit with extreme weather such as an epic drought or blizzard. You need food to fuel and army. Less food meant a population would be vulnerable to enemies, and because of this, people were also more susceptible to being attacked than they were to being triggered to pillage and plunder.

“Weather shocks weakened states and made them easier to defeat in battle,” Rajiv Sethi of Barnard College at Columbia University, who co-led a study recently published in PNAS with colleague Tackseung Jun of Kyung Hee University, told SYFY WIRE. “This made affected states more cautious about initiating attack, and also made rivals more eager to attack them.”

Humans can turn violent in an instant. This has been replayed over and over throughout history, for every reason imaginable. As if that wasn’t enough, the influence of weather that we have no say over can be a deciding factor in another thing beyond our control — whether warriors armed with spears and swords and daggers are going to bust through the gates at any second. Ancient Koreans evidently knew this too well.

There was hardly anything previously known about the effect of weather on war. Sethi and Jun wanted to investigate how weather extremes sparked conflicts back in time, because with climate change threatening us, the same phenomenon could come back to haunt us.

There were two main triggers that set off an attack. Desperation was sometimes behind starving armies invading neighboring city, frantically searching for any food and resources they could find and killing everyone in their way. Opportunistic invasions were more common. In this case, opposing forces were not literally dying for food. It was the food insecurity suffered by the victims that gave them the chance to close in and take over. They found a weakness in a city that may have been taken down by drought and strategically planned an attack to take advantage of that vulnerability.

“Most conflicts at the time (and many today) were very labor intensive, fought by land armies without the kind of long-range weapons now in use,” Sethi said. “These armies had to be equipped and fed, which meant that people had to be moved out of agriculture. Food insecurity made this harder to accomplish.”

Goguryeo, Baekje, and Silla were three ancient kingdoms that had conquered the Korean peninsula between 200 BC and 600 AD. That still didn’t stop battles between them or invasions from neighboring Chinese dynasties as well as Manchurian and Japanese armies. The Samguk Sagi, or History of the Three Kingdoms, documents conflicts in explicit detail, from where a battle took place to who was in combat and how long the fighting was dragged out. Some wars lasted for years. Many ancient historical accounts describe rain or famine lasting for years on end, so it should be no surprise that military conflict associated with weather that debilitated one of the entities involved lasted for the duration of hardship.

There was no such thing as a weather forecast in 77 AD, when Goguryeo was buried in a staggering 3 feet of snow. Drought was the most common misfortune to fall on all three kingdoms, but the Samguk Sagi also documents that precautions were eventually taken. The records tell of drought around 300 AD, during which a high-ranking official asked the king of Goguryeo to halt renovations to his palace, because the workers would instead be able to focus their efforts on producing crops. In 82 AD, the king of Silla worried aloud about a possible war when food and weapons were in short supply.

The question that bothers Sethi, and should also be on our minds, is whether hurricanes, tsunamis, and other cataclysmic events brought on by global warming could end in blood.

“We believe that the research is relevant for labor-intensive conflicts within states and across borders, fought at close range, where historical rivalries exist,” he said. “There are many such conflicts ongoing today.”

If history is documented for a reason, the knowledge of what happened centuries ago in Korea could be our armor against history repeating.