North Korea recently carried out a series of missile provocations in an apparent protest against a resumed South Korea-US combined military exercise.

It fired two short-range ballistic missiles into the sea off its east coast Tuesday. The launch came two days after it test-fired what it claimed to be two “strategic cruise missiles” from a submarine. It is the first time that it launched cruise missiles from a sub. Five days earlier, on March 9, it had fired six short-range missiles toward the sea off its west coast.

So far this year, it has fired missiles on six occasions. Last year, it fired ballistic missiles 38 times, including intercontinental ballistic missiles eight times, and launched cruise missiles three times. The missiles it tested are diverse: short-, medium- and long-range, ballistic and cruise. It is also diversifying its launch platforms. They are doing so to make it difficult for the South and the US to intercept the missiles.

North Korea decided to take important, practical war deterrence measures at a meeting of the ruling party’s central military commission presided over by leader Kim Jong-un on March 12, a day before the Freedom Shield military drill began in the South.

Freedom Shield, currently running from this past Monday through March 23, is an annual theater-level combined Korea-US live exercise. It was resumed five years after the Moon Jae-in administration ceased the drills in 2018.

The large-scale drills do involve field maneuvers such as a combined amphibious training of the Marines from both countries, and include an operation to stabilize the North Korean situation after counterattacks. US strategic assets are set to be deployed during the exercise. The North is expected to carry out various forms of provocation. It may further escalate provocations on the occasion of President Yoon Suk Yeol’s visit to Japan Thursday and Friday.

There is a possibility the North could conduct its seventh nuclear bomb test or fire an intercontinental missile toward the Pacific Ocean. Provocations along the maritime buffer zone and in border areas cannot be excluded either.

The possibility of heightened provocations is high considering the present situation of the Korean Peninsula. The US and China are in a fierce competition for hegemony. Pyongyang has become outspoken in flouting UN resolutions and violating military agreements with South Korea. The North's escalating provocations are likely to trigger a mutual chain reaction that will further strengthen the responses of South Korea, the United States and Japan. Amid these circumstances, localized actions similar to past attacks like the shelling of Yeonpyeongdo or the sinking of the Cheonan warship could be repeated.

South Korea must deal sternly with North Korea’s provocations in whatever form by maintaining an impenetrable defense posture. Through the combined exercises, it must show the might of its extended deterrence against the North. Pyongyang should know it will get the opposite of what it wants by escalating provocations. The Korea-US alliance will be strengthened. Cooperation among South Korea, the US and Japan will be stronger. The resumed Korea-US combined military exercise is not up for negotiation.

The North is ceaselessly developing weapons that are difficult to neutralize or intercept, such as submarine-launched cruise missiles. It is imperative for the South to keep up its airtight defense by upgrading its weapon systems. According to the Defense Acquisition Program Administration on Monday, the South Korean military will increase its fleet of F-35A stealth fighters that can penetrate without being caught in an enemy air defense network. In a bid to enhance its antimissile capability, the administration will purchase SM-6 interceptors to be installed on the Navy’s Aegis-equipped destroyers. It will also develop guided missiles capable of intercepting cruise missiles.

Freedom Shield and defense acquisition projects must become a good example of an overwhelming response to the North’s provocations and of a strong US alliance.

South Korea must also manage the situation of the Korean Peninsula closely lest it gets out of control. Needless to say, if any contingency happens, South Korea ought to cope with it resolutely and wisely based on its alliance with the US.