Since the tensions in the Korean peninsula started to intensify, there has been much discussion about what role Australia would play if North Korea attacked one of its allies. First there were questions about the ANZAUS treaty and whether Australia would be obligated to get involved if the war between the United States and North Korea switched from cold to hot. After North Korea fired a missile over Japan on Tuesday, talk shifted to whether and how Australia might come to Japan’s aid in the event of an attack. But Australia already has a military presence in Japan, and has for the last six decades.

Following the outbreak of the Korean War in 1950 the United Nations established a multinational military force based in Tokyo called the United Nations Command, representing 16 nations that sent troops to the conflict. At the time it was under the command of US General Douglas MacArthur. When the command relocated to Seoul in 1957, it left behind the United Nations Command Rear (containing eight nations from the original) at Yokota Air Base, 40 kilometres west of Tokyo. The UNC rear is to be commanded by an Australian (with a Canadian second in command), currently Royal Australian Air Force Group Captain Michael Jansen.

Despite the fact that Japan was demilitarised following World War II, and established in article nine of its post-war constitution “the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes … In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained”, the Command Rear has nothing to do with the protection of Japan.

“The United Nations Command Rear is solely there for the logistical control of the reinforcements that would flow through Japan in the event of conflict between North and South Korea,” director of International Security at the Lowy Institute Dr Euan Graham told Crikey. “An attack on Japan would be an entirely separate issue.”

Of course, the UNC retains its relevance in the current climate, given South Korea is the primary and perennial target of the North; the two are still technically at war despite the 64-year armistice.

US Secretary of Defense James Mattis has already talked about the importance of the United Nations Command in Seoul. Addressing the Shangri-la Dialogue in Singapore back in June, he said:

“We’ve also seen North Korea engaged in proliferation activities, which means those nuclear capabilities are not solely being retained by North Korea in their own defense.  They are actually exporting some of that capability, some of that knowledge.  And so, to us, we want to stop this.  We consider it urgent.  But at the same time, we are working right now diplomatically and economically. And we obviously work very, very closely with the United Nations Command. 

“This is not just an American command here, a United Nations Command, and the Sending nations — Sending nations being those that sent troops under the U.N. Security Council resolution in 1950.  Because that war was never ended, those nations are still committed to maintaining the peace on the peninsula. And so, we work, obviously with them as well, in terms of the military options.”

Despite this, even an attack on South Korea would not immediately require an Australian military response. 

“In any legal sense there is no obligation for Australia to become involved in the event of an attack,” Graham said. “It would essentially be a political decision.” 

The government’s rhetoric has certainly not ruled out Australian involvement or military action; Prime Minster Malcolm Turnbull pledged his support to the country in an emergency call with Japanese Prime Minister Shinzo Abe, and told Channel Nine that the “risk of war gets greater all the time”. He also echoed Kim Jong-Un’s “suicidal” rhetoric, saying “the reality, however, is that if [Kim] starts a war, he’ll lose it ­instantly, so it would, in effect, be a suicide note on his part”.

All of which would be quite terrifying enough if the rogue state hadn’t just fired a missile across Japanese territory.