President Yoon Suk Yeol warned Tuesday that the South Korea-U. S. alliance is ready to bring an end to the North Korea regime should it choose to use nuclear weapons.

In a series of events marking the 75th Armed Forces Day, South Korea flaunted its military hardware at an air base in the morning and a massive parade in downtown Seoul in the afternoon.

The parade was the first of its kind in a decade, featuring thousands of troops, including U.S. soldiers.

Yoon attended both the morning ceremony and the afternoon military parade, marking the first time a South Korean president has marched alongside troops and people in the streets of downtown Seoul.

The events commemorating Armed Forces Day, which falls on Sunday, also showcased the South Korean military’s secretive “high-power” Hyunmoo surface-to-surface ballistic missile for the first time.

“The North Korean regime must clearly realize that nuclear weapons can never guarantee its security,” Yoon said in an address during the morning ceremony at Seoul Air Base in Seongnam, Gyeonggi. “If North Korea uses nuclear weapons, its regime will be brought to an end by an overwhelming response from the ROK-U. S. alliance.”

He referred to the acronym for the South’s official name, the Republic of Korea.

Yoon noted that despite repeated warnings from the international community over several decades, North Korea has been upgrading its nuclear and missile capabilities.

“Moreover, it has been blatantly threatening to use nuclear weapons,” Yoon said, adding that this constitutes “an existential threat to our people and a grave challenge to world peace.”

He underscored the significance of the “ironclad” South Korea-U. S. alliance, adding Seoul will further strengthen trilateral security cooperation with Tokyo, in a nod to the Camp David summit, and stand in “close solidarity” with partner countries.

Referring to his bilateral summit with U.S. President Joe Biden in April and the signing of the Washington Declaration, Yoon said the alliance with the United States “has become a more sophisticated nuclear-based alliance.”

He said the two allies will establish a unified response system that “combines U.S. nuclear assets and our non-nuclear assets” through their bilateral Nuclear Consultative Group established through the declaration.

Yoon stressed that the frequent deployment of U.S. strategic assets in the Korean Peninsula will strengthen their joint deterrence against North Korea’s nuclear weapons.

He also warned that the Kim Jong-un regime’s “obsession with the development of nuclear weapons aggravates the North Korean people’s suffering” and violates their human rights.

“We have learned from history that only a strong military can guarantee true peace,” Yoon said. “I will do all I can to build a strong military that instills fear in the enemy and trust in the people.”

South Korean and U.S. top military brass, veterans, personnel from countries that supported the UN forces during the 1950-53 Korean War and members of the diplomatic corps took part in the ceremony, attended by some 6,700 troops and including 200 pieces of military equipment.

“As commander-in-chief of the Armed Forces, I will do all I can to build a strong military that instills fear in the enemy and trust in the people,” Yoon pledged.

During the ceremony, nine transporter erector launchers carrying the Hyunmoo surface-to-surface missiles were paraded through a runway at the air base through falling rain.

The South Korean military’s indigenously developed Hyunmoo missiles series, including ballistic and cruise missiles, are key components of the Korea Massive Punishment and Retaliation (KMPR) plan, which would target North Korea’s leadership and military command as a part of the three-axis defense system.

South Korea’s so-called “K-3 strategy,” designed to deter North Korea’s escalating missile and nuclear weapons threats, is comprised of the Kill Chain preemptive strike system, the Korean Air and Missile Defense (KAMD) system, which would destroy incoming missiles; and the KMPR.

South Korea’s long-range surface-to-air missile (L-SAM) system, currently under development, was also unveiled to the public for the first time. The L-SAM is designed to shoot down an incoming ballistic missile at altitudes of 50 to 60 kilometers and is a part of the KAMD program.

Other equipment included K2 main battle tanks, K9 self-propelled howitzers, Chunmoo multiple rocket launchers, Patriot and Cheongung II medium-range surface-to-air missile systems, attack drones and next-generation light armed helicopters.

However, an airshow involving the Air Force’s Black Eagles aerobatic team and formation flights involving KF-21 fighter jets, F-35A stealth fighters and other aircraft was canceled due to the rain.

Later in the day, South Korea mobilized some 3,700 troops for a large-scale military parade in the streets of downtown Seoul to mark the 75th founding anniversary of the country’s armed forces, which falls on Oct. 1.

This was the first military parade in the downtown area since 2013.

The street parade stretched from Sungnyemun to Gwanghwamun, with troops from the South Korean Army, Navy, Air Force and Marine Corps and never-seen-before missiles, tanks, unmanned aerial vehicles and other hardware passing through the heart of Seoul. Yoon was spotted in the procession despite the pouring rain and later gave word of encouragement to the troops from Sejongno.

Likewise, 300 troops from the Eight U.S. Army, under the U.S. Forces Korea (USFK), marched alongside the South Korean military for the first time.

Police blocked off major roads, controlling traffic in downtown Seoul including all roads entering the Namdaemun and Gyeongbok Palace areas Tuesday afternoon.

The South Korean military showed off its new Hyunmoo ballistic missile through a short video clip in the Armed Forces Day celebrations last year for the first time, but this is the first time it has been paraded before the public.

The name Hyunmoo refers to a mythical beast described as the “Guardian of the Northern Sky.” The latest version, a variant of the Hyunmoo-4, is a surface-to-surface ballistic missile. Because of its massive size, it is referred to as a “beast” and reportedly can carry a nine-ton warhead. Military experts have called it an optimal weapon system for destroying underground bunkers, comparing its capabilities to that of a tactical nuclear weapon.

Military officials Tuesday didn’t clarify if the unveiled Hyunmoo missiles were a part of the Hyunmoo-4 series or a new Hyunmoo-5 series.

In 2020, South Korea tested a new Hyunmoo-4 short-range ballistic missile that could carry a two-ton warhead. In comparison, the Hyunmoo-2 ballistic missile could carry a 500-kilogram warhead. In September 2021, a successful test of the Hyunmoo-4 was conducted from a submerged submarine.

BY SARAH KIM [kim.sarah@joongang.co.kr]