SEOUL — When Washington and Seoul warned earlier this year that North Korea was planning its seventh nuclear weapons test, most South Koreans hardly batted an eye. Many in the South have grown so used to North Korean saber rattling that they often dismiss the country’s frequent military provocations as predictable attempts to garner attention.
But this week, North Korea was able to shake the steely nerves of many South Koreans using a weapon much cheaper and less sophisticated than a nuclear warhead.
On Monday, five North Korean drones flying no faster than a speeding car wove through South Korean airspace for five hours — one of them reaching northern Seoul, the capital — before returning to North Korea or disappearing from the South’s military radar. The drones were so unexpected that the South was forced to scramble everything from state-of-the-art fighter jets and modern attack helicopters to prop-engine war planes.
Although this was not the first time North Korean drones have crossed into South Korean airspace, Monday’s breach left many South Koreans voicing concerns on social media about their country’s vulnerability to drone attacks at a time when tensions on the Korean Peninsula are on the rise.
South Korea was put on edge for a second time on Tuesday when fighter jets took off once again, responding to what military officials initially thought could be another wave of North Korean drones. The government sent out emergency text messages advising already anxious residents near the border to beware of “unmanned aerial vehicles.”
North Korea’s Missile Tests
The drones turned out to be a flock of birds.
The South Korean military issued a rare public apology: “Our military detected and chased the five enemy drones but could not shoot them down. We are sorry,” Lt. Gen. Kang Shin-chul said on Tuesday. “Our military’s lack of preparedness has caused a lot of concern to the people.”
Lt. Gen. Kang vowed to increase vigilance against North Korean drones and aggressively deploy weapons to “detect and destroy” them. South Korean fighter jets were dispatched yet again on Wednesday to deal with an unidentified object in the air. This time, it turned out to be a balloon.
Fear of North Korean drones is fueled in part by a long history of inter-Korean hostilities. The two Koreas clashed in naval skirmishes in 1999 and 2002. In 2010, 46 sailors died when a South Korean Navy ship sank in what the South called a North Korean torpedo attack. Later that year, the North launched a barrage of rockets at a South Korean border island, killing four people. The South launched a counter artillery attack across the border.
For months, South Korea has been on high alert for North Korean provocations. This year, the North has conducted a record number of missile tests, proudly claiming the ability to attack the United States, South Korea and Japan with nuclear weapons. The allies have responded by expanding joint military drills, which have in turn prompted the North to expedite its weapons development.
North Korea, suffering from chronic shortages of fuel and spare parts for its armed forces, has been trying to tip the balance of military power against the South by developing an arsenal of nuclear missiles. But the impoverished country has also deployed low-cost weapons like drones, using them as tools of surveillance and aerial attacks based on Chinese and American drone models smuggled from abroad. The country is thought to have up to 1,000 of them, according to estimates by military analysts in South Korea.
North Korea has displayed some of its drones during military parades. It has also demonstrated its drone capabilities by flying a swarm of them during nighttime air shows in recent years.
South Koreans first witnessed the threat of North Korean drones when two of them were found after they crashed in the South in 2014. From the digital camera mounted on one of them, officials retrieved 193 aerial photos, some showing the presidential office in Seoul. South Koreans were shocked that North Korean drones had breached the border undetected.
The camera mounted on a North Korean drone that crashed in 2017 showed that it had flown deeper into the South, flying around an American missile-defense base in the southeast of South Korea.
South Korea’s military said it was able to detect the five North Korean drones on Monday before they crossed the border but had difficulty tracking the small unmanned aircraft with its radar. The drones were also flying close to South Korean villages, making them hard to shoot down without risking the safety of residents on the ground, officials said. A senior presidential aide told reporters on Wednesday that chasing drones with fighter jets was like “deploying artillery to try to kill a fly.”
Critics of President Yoon Suk Yeol of South Korea accused his government of incompetence.
Mr. Yoon’s office said it was under the president’s order that South Korea sent its own drones across the border into North Korean airspace on Monday in a tit-for-tat response. Mr. Yoon’s Defense Ministry said it would spend 550 billion won ($434 million) in the next five years to build weapons capable of detecting and destroying drones.
For his part, Kim Jong-un, the leader of North Korea, has spent the week at the Workers’ Party meeting in North Korea, setting “new key goals” for an ambitious arms buildup in 2023, the North’s state media outlets said on Wednesday.