As confrontational rhetoric between the two countries continues to ramp up and North Korea continues its quest to build missiles capable of launching a nuclear strike on the US, Prof Robert Patman says there is legitimate reason to worry.
However, he believed a change in circumstances in the region, as China took a tougher line on its southern ally, meant it was possible US President Donald Trump's stronger stance could work.
The US leaving open the option of a pre-emptive strike was a high-risk, high-reward policy.
It could pay off in the form of denuclearisation or North Korean leader Kim Jong-un's regime falling, but could also result in military confrontation.
''It's dangerous.
''I think many people are worried about this looming confrontation between two potentially unstable characters.
''There is a lot of debate in the United States about whether international security should be resolved in a way which involves two self-absorbed and highly unstable people,'' Prof Patman said.
The good news for the US and the world was Mr Trump had a few capable people around him and had previously changed his position on their advice, including on Nato and Syria.
It was too early to say whether the US change towards a more confrontational policy was the right move, as the situation could ''quickly spiral out of control''.
''There are a number of areas where miscalculation could occur and it remains a very volatile and delicate situation.''
North Korea had the capability to cause serious damage if it struck South Korea.
It was possible combined pressure from the US and China could cause Mr Kim ''lash out'' and create some sort of confrontation.
China's change in stance since President Xi Jinping met Mr Trump earlier this month significantly altered the situation.
''Several important things have happened since that meeting, which has completely changed the landscape, in my judgement.''
China had applied economic pressure on North Korea by blocking its coal exports to China, reduced flights between the two countries' capitals and moved more than 100,000 troops to their land border.
North Korea is hugely reliant on Chinese support and it was possible this pressure could have dire consequences for North Korea's ability to feed its own people and ultimately for Mr Kim's efforts to stay in power.
''I think the Chinese genuinely have come to the view that all other means of trying to influence this regime have been exhausted,'' Prof Patman said.
The change in landscape and US pressure might make it difficult for North Korea to continue ignoring global pressure to denuclearise.
But Mr Kim may struggle to sell denuclearisation to domestic audiences, because much of his legitimacy comes from having foreign adversaries.
