President Donald Trump has promised to unleash “fire and fury” on North Korea and to “totally destroy” the country if it continues to threaten the US or its allies. His administration even recently considered potentially launching a small, limited military strike — what his aides described as a “bloody nose” — if Pyongyang conducted another missile or nuclear test.

But a decorated former South Korean general said this week that North Korean soldiers would fight foreign invaders with nearly religious zeal in the name of their leader, Kim Jong Un, if under attack.

“I try to explain to the Americans — if we have to go into North Korea, it is not going to be like going into Iraq or Afghanistan. It’s not going to be like toppling [ex-Iraqi President Saddam] Hussein. This would be more like trying to get rid of Allah,” retired Lt. Gen. In-Bum Chun told a London think tank audience Wednesday.

“I have had the opportunity to speak to North Korean soldiers who have defected to South Korea — and you cannot imagine how indoctrinated they are,” he continued. “These are people who have defected, and yet there is still an innate belief in their system which is close to ridiculous.”

Chun has firsthand knowledge of what he’s talking about. He spent nearly 40 years in the South Korean military, including a stint leading the country’s special forces, before retiring only about 18 months ago. That means he spent his entire professional life studying North Korea through the eyes as a military professional who knew he might one day have to fight it.

And some of what he describes is pretty frightening. North Korean pilots would likely use their planes in kamikaze-style attacks, since the aircraft are too old to reliably fly well over long periods of time. That matters since the North Korean air force has around 1,000 planes. Plus, North Koreans receive 100 hours of training on how shoot a weapon a year starting at the age of 14, underscoring how militarized the society is.

But the crux of Chun’s argument is just how loyal North Korean troops and citizens will remain to Kim, even during a foreign invasion. That’s because the country has a system in which North Koreans spy on other North Koreans. If anyone so much as utters a bad word about the regime, that person could go straight to North Korea’s gulags — which a report last year claimed are as bad as Nazi camps.

It’s important to note that a war with North Korea is still very unlikely. North and South Korea are currently engaged in diplomatic negotiations for the first time in more than two years. On January 4, North Korea reopened a military crisis hotline with its southern neighbor after nearly two years of silence, a move that could lower the chances of an accidental war between the two longtime foes. And on Tuesday, Pyongyang agreed to send its athletes to the Olympics in South Korea next month.

War, in other words, may not be imminent. But it’s important to know exactly how bloody one would be.

North Koreans see their rulers as literal gods

It’s worth highlighting the simple reason Chun used religious language to describe why North Korean soldiers would fight so aggressively: They revere members of the Kim family, who have led the country for decades, as gods.

The first leader was Kim Jong Un’s grandfather, Kim Il Sung, who was in power from 1948 to 1994. He is still known today as the “Great Leader” and the “Eternal President,” and monuments glorifying his reign are everywhere in the country.

When Kim died at the age of 82, the Korean Central News Agency, the country’s state-run news organization, published a glowing seven-page announcement that said “he turned our country, where age-old backwardness and poverty had prevailed, into a powerful Socialist country, independent, self-supporting and self-reliant.” He was, as the news agency concluded, the “sun of the nation.”

North Korean propaganda highlights the racial purity of the country and also recalls how it endured under foreign occupation over decades. Songs are written about these themes, and colorful posters make their way even into rural areas hundreds of miles away from the capital.

Since Kim Il Sung’s death in 1994, his son and grandson, Kim Jong Il and Kim Jong Un, respectively, have carried on his legacy. However, the current Kim has made some economic reforms and put much more emphasis on improving the nuclear and missile programs. Still, they purposely demonstrate in their own propaganda how closely they to hew to Kim Il Sung’s style of governance.

Kim Jong Un even goes out of his way to look as much like his grandfather as he possibly can in hopes that he will inspire the same admiration his grandfather did.

More than 400,000 North Korean soldiers died or went missing fighting for the Kim Il Sung in the Korean War. The frightening reality is that many, many more might be willing to fight to the death if war came to the peninsula once again.