Missile tests: how North and South Korea became locked in a dangerous arms race

Recent tit-for-tat missile tests on the Korean peninsula have ratcheted up tensions in the region. On September 15, North Korea launched two short-range ballistic missiles off its east coast, just two days after it tested a new long-range cruise missile capable of reaching targets in Japan and South Korea. Hours later, South Korea tested a new submarine-launched ballistic missile, making it one of only seven countries with this technology.

This has been reported as the latest development in an arms race on the Korean peninsula. But the military purpose of ballistic missiles for the DPRK (North Korea) is completely different from that of those developed by its neighbour to the south.

Parallel to the development of a nuclear weapons capability, the DPRK started to build and deploy ballistic missiles in the 1980s. Their main purpose was to provide the means to deliver nuclear warheads against “enemy targets” in the event of a conflict. South Korea, meanwhile, renounced nuclear weapons in 1975 when it ratified the Nuclear Non-Proliferation Treaty. The country initiated a limited conventional missile programme in the late 1980s.

North Korea’s missile programme developed from cold war-era Soviet missiles with subsequent modifications to increase range and accuracy. Pyongyang’s aim has been to develop a credible nuclear deterrent (or threat) against a nuclear superpower on the other side of the world – the United States.

This required ballistic missiles with an intercontinental range as well as a significant stockpile of tested nuclear devices. North Korea’s programme has continued to depend heavily on Soviet/Russian technology with some other imports, most likely from China.

The North’s medium-range missiles can threaten Japan and South Korea. While South Korea and the US are thought to be North Korea’s most likely adversaries in any conflict, threatening to destroy South Korea is problematic for a North Korean leadership ostensibly dedicated to Korean unification. The Hwasong-15, tested in 2017, has come closest to demonstrating a capability of targeting the United States.

Recent developments nevertheless could dramatically change the strategic situation on the Korean peninsula and northeast Asia. In response to the North Korean threat, South Korea and Japan have deployed ballistic missile defences provided by the US. But these systems would only provide imperfect protection if North Korea were to launch a determined nuclear attack at very short range.

South Korea was initially provided with missile technology by the US in the 1970s. The country’s indigenous missile programme started by reverse engineering US missiles and has developed from there. In June it was announced that the US and South Korea had agreed to scrap restrictions on the range and weight of the latter’s missiles agreed in 1979.

The aim of South Korean ballistic and cruise missiles armed with conventional warheads is to target North Korean command-and-control centres and hardened military facilities buried deep underground. What South Korea calls its “kill chain” is designed to aggressively respond to any level of North Korean aggression with “massive punishment and retaliation”.

The successful launch of its submarine-based missile shows that South Korea – whose annual military budget is well in excess of North Korea’s entire GDP) has highly modern and versatile forces that mean it can at least hold its own in a conventional conflict. But due to the threat of North Korea’s nuclear weapons programme, South Korea needs to continue to rely on US extended nuclear deterrence.

Show of strength

For North Korea, these tests are not primarily designed to improve missile designs. Instead they are about demonstrating to its own population that North Korea is a great and powerful nation. It also has the aim of demonstrating its military strength to potential adversaries, especially South Korea and the United States.

North Korea also uses these tests as a way to mitigate diplomatic isolation and as leverage to generate international aid. During the Trump administration, the accelerating scale of North Korean nuclear and missile testing resulted in Trump first threatening “fire and fury” followed by the summits with Kim Jong-un. The summits achieved little, except to enhance Kim’s public standing – both internationally and with his own public.

Increasingly severe international sanctions have hit North Korea hard – although Pyongyang has invested heavily in trafficking and moneylaundering routes to mitigate the impact on North Korean elites. A UN expert panel concluded earlier this year that “the North Korean regime is evading sanctions at a faster rate than the international community is able to tighten the sanctions regime”.

This has meant that while that there is now a serious risk of another major famine, the country’s weapons programme has continued at a steady pace. It now has plenty of capacity to make its own missiles.


The resumption of missile tests and the restart of operations of the Yongbyon nuclear reactor signal a renewed effort by the DPRK to push ahead with its nuclear weapons programme. Once again, this will primarily serve a political end – to turn around the political and economic impasse that it finds itself in.

The Biden administration, meanwhile, is trying to position itself between the policy of “strategic patience” (waiting for North Korea to implement its previous commitments to denuclearise) of the Obama administration and the “grand bargain” (full diplomatic relations and economic benefits in return for giving up nuclear weapons) promoted by Trump.

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North Korea, nuclear proliferation and why the ‘madman theory’ is wrong about Kim Jong-un

Washington remains committed to forcing North Korea to halt its nuclear weapons programme, but has failed to articulate how that might be achieved. In the absence of credible diplomatic initiatives, the tension between North Korea on one side and South Korea and the US on the other is likely to grow. Expect further missile launches – and possibly nuclear weapons tests – in the near future.

The Conversation

Christoph Bluth received funding from the Korea Foundation.

Owen Greene has received funding in the past from Japan's Research Council, the Foreign Ministry of Japan; and from the USA State Department and Ford Foundation. He is co-founder and Chair of the Board of the independent non-profit NGO VERTIC (Verification Research, Training and Information Centre), which has research projects relating to the implementation of UNSC sanctions on DPRK..