Scenarios could include the North Koreans accidentally hitting targets at the US island territory of Guam, which would lead to an American reaction. Photo / AP
With tensions remaining high in the Korean peninsula, experts are alert to the risk of the conflict escalating out of hand and spreading across the world.
While many have focused on the prospect of a nuclear conflict, the possibility of a conventional war between North and South Korea could be almost as damaging.
Professor John Blaxland, director of the ANU Southeast Asia Institute, said there were some plausible scenarios that could unfold and engulf many neighbouring states and world superpowers in military action.
"There is a clear prospect of a conflict on the Korean peninsula escalating out of hand," Prof Blaxland told news.com.au.
"Although we are mindful about avoiding war, it could be ratcheted up incrementally."
Blaxland said North Korean leader Kim Jong-un may begin a "tit-for-tat" action if things got heated with the United States.
Scenarios could include the North Koreans accidentally hitting targets at the US island territory of Guam, which would lead to an American reaction, such as the sinking of a North Korean warship as punishment.
In retaliation, North Korea may launch a military barrage against South Korea and may also activate sleeper cells to undertake sabotage operations and foment unrest in the country.
"It could be a significant challenge for South Korea to contain unrest in the country and this could be enough political imperative for them to act as well," Blaxland said.
This may unleash a further military barrage between the two neighbouring countries and with the South Korean capital of Seoul so close to the border, it could potentially cause tens of thousands of casualties.
But the conflict may not end there.
Blaxland said fighting on the Korean peninsula could prompt China and Russia to also get involved.
He said Russia might want to show support for North Korea out of resentment about American assertiveness over new sanctions aimed at the regime, which is specifically targeting companies but also individuals doing business with North Korea.
"Friends of [Russian President Vladimir] Putin are already being targeted by the sanctions," he said. "They are annoyed."
"If Russia feels sufficiently slighted ... perhaps they would use the destruction in the Korean peninsula to do something more assertive in the Baltics," he said.
Russia could fire a missile or use its special forces to foment unrest in countries like Latvia, Lithuania or Estonia.
This would bring up questions about where the threshold was for the use of nuclear weapons.
"It is hard to know where this threshold is but if someone, anyone crosses it, we are in a very dark space," Blaxland said.
Another scenario could arise if Russian forces were accidentally hit by Americans trying to retaliate against North Korea. This could prompt a response from Russia fuelled by outrage domestically if citizens were killed.
"If a Russian was killed and this was publicised in the media and there was a general strong reaction, Putin may want to do something to demonstrate his strength," Blaxland said.
"You can see how that kind of thinking could lead to miscalculation.
"Should tempers run high, should there be humiliation, should the nation's pride be hurt, should [US President Donald] Trump or Putin perceive the need to escalate, there could be a miscalculation."
Similarly, China, another nuclear power, is also unhappy about American sanctions against North Korea, which is targeting its citizens too.
China is located right on the border of North Korea and does not want the US right on its doorstep. If there was an escalation on the peninsula China could also chose to insert forces, although Blaxland did not think this was likely.
Another unlikely scenario could be the involvement of Japan. But Japan is within striking range of North Korea and is also an American ally so could be targeted.
"If a North Korea missile strike were to hit Japan, all bets would be off, that would change the dynamics," Blaxland said.
Australia could also be drawn into the conflict through its ANZUS Treaty with America.
"We may provide ships for the area, aircraft, fighters, logistics support and aerial surveillance," he said.
But Blaxland said he was reasonably confident these scenarios were avoidable even though they were still quite plausible.
"There's a spectrum of various factors, all of which are plausible and intersect in different ways, that could rapidly escalate but which planners are aware of and seek to mitigate the risk of," he said.