North Korea Launches More Missiles, and U.S. Bombers Fly Over the South

North Korea fired four short-range ballistic missiles off its west coast on Saturday morning, and hours later two American B-1B supersonic strategic bombers flew over ​the ​Korea​n Peninsula​ in ​the first deployment of its kind since 2017.

North Korea has launched as many as 85 missiles this year, more than in any previous year, including 23 fired on Wednesday alone. It not only tested a new intercontinental ballistic missile under development, but also fired a flurry of short-range missiles to counter the United States and South Korea as the allies stepped up joint military drills.

One ​such drill, ​code-named ​Vigilant Storm, which involved about 240 warplanes ​from both allies, ended on Saturday after a six-day run. The drill was scheduled to end on Friday, but was extended a day after North Korea launched an ICBM on Thursday.

The four short-range ballistic missiles on Saturday flew 81 miles​, according to the South Korean military​.

North Korea has typically protested joint military drills by the United States and South Korea, accusing them of preparing to invade, and cited them as a reason that it was building its nuclear arsenal.

But this year, its reaction has been more aggressive.

It has fired a burst of missiles during ​such ​joint military drills by the allies, launching them from across North Korea. By sending them from many different locations, even from an underwater silo, the North sought to demonstrate that it could thwart the allies’ missile defense system, military experts said.

Although the North Korean air force is chronically short of fuel and spare parts, it also sent up as many as 150 planes in an exercise last month, according to state-run North Korean news media. Three times since early last month, North Korean military aircraft have flown close enough to the border with South Korea for the South to scramble its own fighter jets.

North Korea has also fired hundreds of artillery shells and rockets into buffer zones north of the inter-Korean maritime borders that the two Koreas ​created when their leaders met in 2018. ​Both sides had agreed, as a tension-reducing step, not to fire rockets and artillery there​.

N​orth Korea may have gained a sense of empowerment ​from its growing nuclear arsenal​, becoming increasingly daring in its military provocations, analysts said.

For their part, South Korea and the United States demonstrated their own combined air power superiority this past week, with warplanes conducting ​a record 1,600 sorties during the Vigilant Storm exercise.

On Saturday, two B-1B Lancer bombers, taking off from Guam, the U.S. territory in the West Pacific, flew over South Korea, flanked by four South Korean F-35A fighter jets and four American F-16 jets, according to the South Korean military. The United States last deployed B-1B bombers​ over South Korea​ in 2017, when North Korea conducted its last nuclear test, as well as test-firing its first ICBMs.​

The North Koreans are particularly sensitive about long-range American bombers over South Korea, after U.S. aerial bombings leveled their country to ashes during the Korean War in the 1950s.

Sending the ​B-1Bs, which had been scheduled in advance of North Korea’s Saturday morning missile launch, was part of Washington’s commitment to its so-called extended deterrence. By deploying supersonic and long-range bombers to the Korean Peninsula, the United States highlighted its commitment to defend South Korea in times of conflict there.

Jitters over the North Korean nuclear arsenal have been rising in South Korea since ​North Korea adopted a ​more aggressive nuclear doctrine​​, openly declaring that it would use nuclear weapons if threatened​. It has also conducted military exercises that​ it said​ involved ​the ​mock launch​ing of nuclear missiles at South Korea.

North Korea’s leader, Kim Jong-un, views expanding his nuclear and missile force as essential to ensuring his regime’s security, increasing his leverage in future arms control talks with Washington and tipping the balance of military power between North and South Korea in the North’s favor​, according to analysts​.

When Defense Secretary Lloyd J. Austin III met his South Korean counterpart, Lee Jong-sup, in Washington this past week, ​he warned that “any nuclear attack​” by the North would “result in the end of the Kim regime,” according to a joint statement​.

B​ut North Korea vowed to respond to the “hostile” United States and South Korea “with the toughest counteraction​,” according to a statement from its Foreign Ministry late Friday.

The war in Ukraine ​and tensions between Washington and Beijing have made Russia and China less cooperative when it comes to the United Nations Security Council imposing additional sanctions on the North.​ Both China and Russia are veto-wielding members of the council​. That may embolden North Korea to test more missiles​, South Korean officials said.