Andrew O’Neil is Director of the Griffith Asia Institute and Professor of International Relations at Griffith University.  

For those watching developments on the Korean peninsula, the default position is to gauge North Korean behaviour as the barometer for stability and instability in the region. However, this week, evidence that South Korea is becoming increasingly nervous about North Korea's evolving strategic capabilities — particularly its nuclear weapons delivery capabilities — underscores the growing risks of a major conflict erupting in Northeast Asia as a result of miscalculation or inadvertent escalation.

Comments by President Park Geun-hye that the situation on the peninsula is 'very grave' were accompanied by South Korea's biggest parade of its military strength in decades, including showing off newly acquired Hyeonmu missiles which, in the words of one South Korean official, have the capability of 'striking the office window of the North's command headquarters'. Without even a vague sense of irony, authorities in Pyongyang accused Seoul of engaging in 'an unprecedented display of lunatic hostility'.

This exchange occurred as US Defense Secretary Chuck Hagel was making sympathetic noises in response to intensified South Korean lobbying to defer (yet again) the transfer of wartime operational control of allied forces on the peninsula from Washington to Seoul, which is scheduled to take effect in 2015.

All of this is significant because of the broader story it conveys regarding Seoul's increasing anxiety over North Korea's nuclear program and the threat it poses to South Korean security.

The integration for the first time of specific nuclear threats into Pyongyang's rhetoric during the March-April crisis this year and an assessment that there is precisely zero probability that North Korea will denuclearise (after years of bloated rhetoric from observers about 'grand bargains') has forced South Koreans to seriously ponder what it will be like living with a nuclear-armed DPRK.

A desire for greater extended deterrence reassurance from Washington has led to more detailed US-ROK operational planning to counter North Korean provocations and possible strikes, as well as tighter integration of anti-missile systems through a deterrence-by-denial strategy.

The public release by China last week of a list of dual-use items that it has decided to prohibit from export to North Korea (because they could contribute to Pyongyang's nuclear program) was no doubt read by Seoul as confirmation that Beijing believes Pyongyang is a lot closer to arming its missile force with nuclear warheads than was the case until quite recently. South Korean intelligence on the North's strategic weapons programs is pretty good, but China's is better.

One thing we can be certain of is that there will be further crises on the Korean peninsula. But whereas in the recent past such crises have been defused without escalation to conflict, the new dynamics introduced by North Korea's possession of nuclear weapons increases the prospects for serious crisis instability in future.

To paraphrase Robert Jervis, crisis instability exists when both sides perceive an incentive to strike first out of fear that if they do not, they won't not be able to strike at all because the adversary will pre-empt.

In the Korean peninsula context, this logic will be accentuated by Pyongyang's underdeveloped command and control systems. The natural tendency of any totalitarian government will be to centralise control over the country's prized strategic assets to avoid a fragmentation of its authority. But Pyongyang will also be cognisant of the need to protect these assets by dispersing them geographically, and hedging against a first strike that takes out the central leadership by transferring some pre-delegated authority to local commanders to use nuclear weapons.

Indeed, the very prospect of authority for nuclear use being transferred to local North Korean military commanders could act as a strong disincentive to any US or South Korean decapitating strike directed against the regime's core leadership. South Korean strategists have no doubt thought this through, despite the thinly veiled threats about targeting North Korea's leadership group with precision guided Hyeonmu missiles.

Although it seems highly improbable that the US and its allies would countenance the first use of nuclear weapons in any Korean peninsula crisis, it cannot be ruled out.

American extended deterrence reassurances for South Korea and Japan since the end of the Cold War have had an explicit nuclear dimension, and Washington's decision to undertake high profile overflights of B-52s and B-2s as part of Exercise Key Resolve earlier this year emphasised the continuing operational importance of nuclear weapons in allied planning in Northeast Asia. Nuclear reassurances are seen as crucial in illustrating the depth of the US extended deterrence commitment to allies, but nuclear weapons also have a potential operational role in targeting hardened underground facilities in North Korea, as reflected in the Obama Administration's nuclear targeting blueprint, Operational Plan 8010-08 Strategic Deterrence and Global Strike.

The worrying bottom line is that, from the perspective of Washington and Seoul, the incentives to carry out preventive strikes against North Korea's nuclear infrastructure will become more compelling the closer Pyongyang gets to acquiring a second strike capability. The risk that Pyongyang may try to pre-empt this by striking first is something that will need to be managed extremely carefully in future crises on the Korean peninsula.

If the past is any guide, this test will come sooner rather than later.