This week’s faux artillery duel between North and South Korea, in which both bombarded empty patches of water, highlighted the at times oddball confrontation between North and South Korea.

The North, after warning the U.S. and South Korea to cancel their planned amphibious exercises, registered displeasure by bombarding an empty patch of ocean, just south of the border. The South responded in kind by bombarding an equally lonely patch of ocean, just north of the border. And that was the end of it.

In the 61 years since the ceasefire, North and South Korea have gone their separate ways. North Korea has become impoverished, with an economy 1/35th of New York City’s and a bloated, slowly crumbling military. South Korea has grown to become the 15th largest economy in the world but is facing a declining population.

In response to these trends, the geography, history, and present political situation, both countries have developed homemade, sometimes offbeat weapons.

Weird Smoke Rings

Saturday’s Ssang Yong exercise, held by the U.S. and South Korea, was designed to showcase the ability of both countries to land Marines on hostile beachheads. Waves of AAV-7 amphibious vehicles—also known as amtracs—waddled onto the simulated enemy beachhead, churning white smoke made from burning diesel fuel. Each carried up to eighteen Marines.

The amtracs landed on the South Korean beach four abreast, but just before hitting the beach, something odd happened: giant smoke rings exploded in the sky. A pair of rings, spiky and brown, briefly hovered over each amtrac before being carried away by prevailing winds.

The rings were actually smoke grenades, launched skyward from banks on the amtrac’s turrets. Smoke grenades create instant cover for vehicles on the battlefield. Ideally, the first wave of vehicles would have created a wall of smoke to hide the waves landing behind them.

Unfortunately, the grenades used on the beachhead didn’t work as planned—high offshore winds scattered quickly scattered the smoke before it could obscure the rest of the invasion force. In a matter of moments, it was as though the rings had never been there.

Homemade drones

North Korea has developed its own unmanned aerial vehicle, or “super precision drone plane” as the country’s state news agency refers to them. Six feet long and painted sky blue, two have been found crashed on South Korean territory, the latest on March 31st at Baengnyeong Island.

North Korea military expert Joseph Bermudez Jr. told NBC News the drone “looks like it has a modified fuselage and been fitted with a camera—imagine a model plane with a camera.” According to the Joongang Daily, a similar drone found on March 24th had a Japanese-built engine, with other parts made in China.

One of the drones, found in South Korea on March 24th, had apparently flown over Seoul undetected. The drone had a digital camera mounted on it, with pictures of central Seoul and the Blue House, the official residence of the South Korean president, stored on a memory card.

Not to be outdone, South Korea has a small drone of its own, one with perhaps the best drone name ever: Devil Killer. Described by Korea Aerospace Industries as a “tactical suicide combat UAV,” Devil Killer is designed to perform reconnaissance missions. Optionally, it can live up to its description by crashing into targets and detonating a five-pound warhead.

Five-feet long with a nine-foot wing span, Devil Killer can allegedly fly at speeds of up to 250 miles an hour to ranges of up to 24 miles. Devil Killer can be launched from ships and ground vehicles, and could be used to attack North Korean targets both on the ground and at sea.

Nuclear backpacks

The July 2013 “Victory Day” parade, an annual display of North Korean military strength, featured a curious new sight: a truckload of smiling, waving People’s Army soldiers equipped with unusual backpacks. The backpacks were in North Korean camouflage and adorned with a large international radiation symbol.

North Korea officials claimed that the backpacks contain hazmat suits, but the backpacks are so small they seem incapable of storing a useful radiological suit. Some observers suggested the backpacks could be so-called “backpack nukes”, but North Korea is thought to be far from the technology to sufficiently miniaturize a nuclear weapon.

Nuclear proliferation expert Jeffrey Lewis, writing in Foreign Policy, has suggested that the backpacks are some kind of radiological device, such as dirty bombs. North Korean special forces troops would infiltrate the devices into South Korea and use them against strategic targets. Alternately, should China attempt to intervene in North Korea’s internal affairs, the North Koreans could use the devices to seal the Chinese border with radioactive no-go zones.

Whatever the backpack is, North Korea wants the world to know it has it… even if it doesn’t. Uncertainty is one of the impoverished country’s best weapons.

Gun-toting robots

Like the rest of Asia, South Korea is experiencing a falling birth rate and shrinking population. South Korea is finding it increasingly difficult to maintain a large standing military, which is set to contract by a fifth over the next decade in part due to demographic reasons. As a result, the country has turned to a machinegun-toting robot to help guard the 160-mile long border with North Korea.

The robot, built by Samsung, is known as SGR-A1, or Security Guard Robot A1. Equipped with both daylight and infra-red cameras, SGR-1 can identify targets at ranges of up to 2.5 miles. The robot also has built-in voice recognition and a speaker that a human operator can use to challenge suspected intruders.

SGR-A1 scans autonomously, and once it detects suspected intruders alerts the operator. Up to 16 SGR-A1s can be monitored by a single person. If the intruders are deemed hostile, the operator can engage manually or sit back and let the robot engage. The robot is armed with a light machine gun and automatic grenade launcher.

South Korea originally wanted up to 1,000 of the robots to man the Demilitarized Zone, at up to $200,000 each. This makes the SGR-A1 much more expensive than the average South Korean draftee private, who earns less than $100 a month. On the other hand the robot can replace at least three privates, and the average income in South Korea is $35,400 a year. If each SGR-A1 robot can stand watch for just two years, South Korea comes out ahead.

Barring reunification, a North Korean collapse or war, the trends that created these weapons will undoubtedly continue. North Korea will continue to focus to homemade designs, and getting the biggest bang for its buck. South Korea will focus on automation and firepower. The Korean peninsula is becoming the Galapagos of the military world, an isolated place that might well one day spawn weapons unlike any other on the globe.