There are few strategic policy issues as intractable as those appending to North Korea. A war would result in millions of Korean casualties and in the destruction of essential infrastructure, industrial capacity and urban habitation on the Korean peninsula. In such a conflict, the US would inevitably prove victorious and the level of destruction visited on North and South Korea would probably be catastrophic. The strategic impact of the conflict would be felt well beyond Korea and could seriously destabilize East Asia.

Viable solutions to the impasse over the denuclearization of the DPRK have been elusive. A diplomatic solution acceptable to both sides seems unreachable. A preemptive strike by either the US on North Korea or by the DPRK on US forces or the US homeland, resulting in a major war on the peninsula, could produce an even more dangerous situation in East Asia than the current stand-off.

At absolute worst, China, and possibly Russia, wouldn’t remain neutral during a conflict—raising the possibility of an East Asia–wide war. But even if both stood by, in a postwar situation it’s unlikely that China would then tolerate US occupation of the Korean peninsula; nor would Russia be comfortable with US troops on its Asian border. The US would have objections to China or Russia assuming control of DPRK territory. After the conflict, the Republic of Korea would likely be in no position to take over control of the north. Control of the peninsula would become a very important and challenging matter.

A Korean war can be expected to be at least as catastrophic as any contemporary conflict. Both sides would deploy sizeable and capable regular military forces. Apart from widespread destruction, massive migration of Koreans fleeing the conflict zone could be expected, heading to Japan, China, Taiwan, the Philippines and perhaps Australia. Ten million people reside in Seoul, 51 million in the ROK and 25 million in the DPRK.

The ROK is a modern, advanced trading economy. Rebuilding the social and economic infrastructure on the peninsula after a DPRK attack would be a massive financial burden and an enormous organisational task that neither the US, the EU nor Japan would be prepared or able to take on. Providing peacekeeping troops or civil administration would prove enormously problematic for the UN—given the Security Council vetoes of China and Russia—and violence might become entrenched. The postwar conditions on the Korean peninsula could be an ongoing security problem for decades.

The broader strategic significance of the Korean peninsula stands out. China and the US would both have a deep strategic interest in dominating the peninsula. The Tsushima Strait at the entrance to the Sea of Japan between Bosan and Fukuoka is a mere 200 kilometers wide. Possession of the peninsula would potentially provide China with total security for naval operations in the Yellow Sea and easy access to dominate the Sea of Japan and the East China Sea. Together, China and Russia would have an effective chokehold on the Sea of Japan. Chinese aircraft based on the peninsula would threaten Japan directly. Conversely, China would strongly resist any US presence on the peninsula because that would imperil core Chinese strategic ambitions in maritime East Asia.

In the wake of a major war on the peninsula, the strategic competition between the US and China in East Asia would intensify dangerously, Japan’s security would be eroded, and contention over islands in China’s littoral seas would increase.

Australia’s key security and economic interests would be under even more threat in this post-conflict scenario than they are now from a North Korean regime with a relatively limited strategic nuclear capability. Australia poses no serious military threat to the DPRK at present, and the North Korean regime, which is obsessively focused on the US as the existential threat, poses no military threat to Australia. Currently, the ROK ranks fourth among our bilateral trading partners. In 2015–16, Australia exported $19.7 billion in goods and services to the ROK, including substantial amounts of coal, iron ore, aluminum, beef, sugar, medicaments and wheat. The adverse economic impact of war on the peninsula would be significant.

Prime Minister Turnbull has indicated that Australia would invoke ANZUS were the DPRK to attack the US. That would primarily be empty symbolism, given Australia’s inability to affect the outcome of any conflict. It would also represent a failure—or an absence—of Australian strategic policy. Putting aside what Australia’s position would be if the US acted pre-emptively, it seems self-evident that Australia’s primary interest is in avoiding a conflict.

The chance of a degree of disruption, uncertainty and strategic danger spreading beyond the conflict zone raises questions of planning and preparedness for the Australian government. A post-conflict situation that would engender far higher tensions and confrontation between China, Russia and the US must be factored into Australia’s strategic policy decisions. The government must explain where it’s prepared to take the nation in support of the US.

Australia needs a comprehensive and transparent public and parliamentary debate in which the government sets out its view of Australia’s interests, the threats to those interests, Australia’s capacity to manage or influence those risks and the preferred end state. The Australian public must understand what’s at stake.

The government needs to reassure the public that it has a comprehension of the strategic issues in East Asia—and how a new Korean war might engage the interests of the major powers—beyond the emblematic invoking of ANZUS. It needs a strategic policy.

This first appeared in ASPI’s The Strategist here.