Could North Korea go to nuclear war with US? The possibilities and future scenarios explained

Every week now seems to see new provocations between Donald Trump and Kim Jong-Un. But what do they actually mean?

The tensions have led to increasingly fraught exchanges, military drills and missile tests – each of which has led to more threats from both countries.

In recent weeks, Mr Trump has called for "fire and fury like the world has never seen" to be unleashed on North Korea, and has presided over military drills that have enraged the North Koreans. For their part, they have claimed Mr Trump has declared war on the country and that it could now shoot down US military planes.

But is the world really on the brink of a Third World War? Experts say probably not, while pointing out that it is easy to see how we might get there.

A general consensus is that the US President's statements are just bluster, although many emphasise the fact that bluster has an unfortunate history of leading to war.

The new escalation is the latest in an ongoing ratcheting up of tensions between Pyongyang and Washington, and came after a report that claimed North Korea had developed nuclear weapons small enough that they could be flown all the way to the US mainland and detonated there.

After that came what prominent arms control expert Jeffrey Lewis has described a “carnival of bellicosity”.

Mr Trump‘s “fire and fury” statement is unprecedented in US relations with North Korea and markedly similar to the kind of rhetoric that emerges from Pyongyang.

North Korea appeared to call the US leader's bluff within hours of his statement, announcing it was exploring the possibility of attacking Guam, a US pacific territory that among other things houses strategic bombers.

Crucially, this statement appears to have been formulated in response to the US flying two B1-B bombers over the Korean Peninsula on Monday, a repeat of a similar operation carried out in July – and therefore not in response to Mr Trump's warning.

Rex Tillerson, the President's foreign policy chief, moved to calm the situation and advised the US public not to worry.

The message of de-escalation appears not to have influenced Mr Trump, however, who woke up and tweeted that the US nuclear arsenal was “more powerful than ever before” – though adding that he hoped never to use it.

Nevertheless, the US leader's shift to outright belligerence towards North Korea has given rise to widespread fears around the prospect of a major global nuclear conflict, the fallout from which would inevitably see the destruction of large parts of the world.

No, probably not, according to experts contacted by The Independent. Mr Trump’s comments offer a significant and meaningful change in the rhetoric being exchanged between North Korea and the US – but they appear to be just rhetoric, for now.

“The first thing I would say is that I’m not sure that Mr Trump’s comments change the fundamental calculus on the Korean peninsula, in the North or in the South,” said James Hannah, assistant head of the Asia programme at Chatham House.

“What’s obviously changed is the Trump factor and he has in a way emulated the North Korea bellicosity approach.”

Even the President’s voice is just one among many – albeit that of the Commander in Chief – in the White House, and is by far the most aggressive.

Rex Tillerson said there was no “imminent threat” and that “Americans should sleep well at night”, while explaining that the President had adopted such a confrontational tone because this was language that Kim Jong-Un could understand.

That does not mean there was not reason to be concerned.

“Having followed North Korea for a long time, I am getting more worried,” said Aidan Foster-Carter, honorary senior research fellow in sociology and modern Korea at Leeds University.

“I worry about rhetoric getting out of control on either side and this leading to a miscalculation of some sort.”

Professor Foster-Carter stressed that he was not suggesting Mr Trump’s comments or the US approach was anything like that of North Korea, only that there was an increasing degree of public enmity between the two sides.

North Korea demonstrates better than any nation that bluster is important.

“I worry about loose rhetoric,” said Jeffrey Lewis, an adjunct professor at the James Martin Centre for Nonproliferation Studies.

“Because I worry that allies or the North Koreans won’t understand that it’s just bluster.

“But having said that, I don’t believe that it’s evidence that the US is going to attack the North Koreans.

"In a strange way it’s reassuring because it’s clear he doesn’t know what to do; if he had some plan to attack them, he wouldn’t be talking about his plan to attack them.”

Perhaps the most terrifying thing about the situation is how impossible that question to answer; there are simply too many disparate elements, each of them unpredictable on their own and amounting to a situation in which almost anything could happen.

“If the calculus hasn’t changed, what is being introduced is a greater level of unpredictability and rhetorical tension,” says Mr Hannah. “Which has a number of knock-on effects.

“If the US is unpredictable, Trump supporters might see that as a pro – taking a harder line and putting pressure on the North and conceivably on China, by eventuating the threat.

“But equally, that unpredictability doesn’t wash well with US allies in the region, like Japan or South Korea. It creates a sort of echo chamber of inflated rhetoric.”

And with Mr Trump in power, rhetoric tends to dominate the debate – and often become the debate.

“If you do raise the rhetoric then I suppose there’s a greater worry that the chance of action in some quarters is increased,” adds Mr Hannah.

It all really comes down to whether North Korea thinks that Mr Trump’s statements actually mean anything. If he is just blustering – an activity they know well – then very little has changed; if they think that the rhetorical stance is something that puts them in danger, then conflict could arise.

If any conflict were to happen, it is likely that war would break out by accident, not by design. Mr Trump’s comments might be mostly powerful as rhetoric – but wars have been fought over similar rhetoric before.

It’s worth noting that, of course, most people are still against the idea of nuclear wars. That is a fairly safe assumption and means that, whatever is said, nobody is going to choose to drop an atomic bomb on another country happily.

More simplistic military intervention, of the kind that western governments had hoped for when they went into Iraq in 2003, is also probably out of the question.

As soon as North Korea felt it was being invaded, it would likely launch attacks on South Korea; if that happened, the big questions of North Korea’s nuclear range would be less important, since Seoul could be hit by simple artillery. The idea of risking those people for an intervention is all but impossible.

“Worried though I am about Trump I think he would be dissuaded from such a course,” says Professor Foster-Carter. “It would destroy South Korea, it would destroy the alliance; it would be more damaging even than all the conflicts that we’ve sadly grown used to in places like Iraq.”

But it’s not that simple.

“It has become more complicated to the point that concerns of miscalculations are higher, so that’s probably where the danger is,” says Mr Hannah. “In a very complicated situation, I think the fear is of an unpredictable misstep or message that triggers some kind of chain reaction by one party or the other.”

That’s the chief concern about Mr Trump’s comments – that they could be read as a suggestion that something damaging is about to happen, and that they could pre-emptively respond.

And with such a swell of aggressive rhetoric swirling around the situation, any individual incident’s importance is going to be far higher.

The breakdown of negotiations and diplomacy between the US and North Korea also means that any minor event could be significant, since there’s no easy way for either country to address or calm any problem.

Between 1994 and 2003, diplomatic agreements froze North Korea’s nuclear development and made it easier for diplomacy to go on between the country and its adversaries on other issues.

“What that means is when you have a conflict – when there’s a shoot-out on the maritime demarcation line, for instance – you’ve got a way to defuse tension,” said Professor Hazel Smith, author of North Korean Markets and Military Rule. “Today that doesn’t exist.

“So if you have a relatively minor incident on the border, which is still disputed, which is still possible, there is a possibility for it to escalate. That’s how wars start.

“It is dangerous, the situation we have right now, especially when you have so many states with different interests involved.”

If that war happened, the US would ostensibly win it – that much is obvious, and is a key factor in the US military’s thinking. But that part of the world is surrounded by many of the biggest armed forces in the world, and any conflict would be “very, very bloody indeed”, said Professor Smith.

It’s possible that Mr Trump’s comments are part of some master plan, unlikely though it might be.

And the very fact that he is talking about the country is an important break from the Obama administration’s commitment to what it called strategic patience – but which really “was hard to distinguish from neglect”, says Professor Foster-Carter.

“Trump to his credit takes North Korea seriously but does it in such an extraordinary manner," he said.

Anyone minded to think of Mr Trump as a strategic genius, may see his latest comments as evidence of a clearly though-through plan.

Those looking to be sympathetic, may suggest he is trying to match North Korea’s often aggressive commentary with similar attack of his own, or that his lack of care is a result of the “madman theory”, whereby a person behaves so bizarrely that they unsettle opponents and gain power from the perception they might do something crazy.

In some ways, it has the advantage of helping both sides. Both Pyongyang and Washington are led by men who are interested in making the other out to be evil and unhinged, both want to look strong and both can benefit from giving the appearance that, if prodded, they could trigger a nuclear armageddon.

Those are perhaps less likely than the theory Mr Trump is simply wading into a discussion that he feels strongly about. Thankfully, the US leader is surrounded by people who are slightly more sensible – even if they’re not always able to stop him speaking.

The idea of the “fantastic, grim scenario” in which the world is pushed to nuclear was is “unbelievably frightening,” says Professor Foster-Carter. “But I don’t think it will happen because I think, hope and pray there’s enough adult supervision – in the military people, like Mattis and McMaster – and there’s no sensible strike option.”

It’s clear that those generals who now surround Mr Trump – secretary of defence James Mattis, and national security advisor HR McMaster – do not want war, precisely because they are the most acutely aware of the damage it might do.

“One of the ironies is that it’s the generals that are trying to prevent the outbreak of military conflict – to look at alternative ways of what’s going on,” said Professor Smith.

Mr Trump’s comments were in part notable because he did not appear to have taken direction on them – and may not have even planned to say it at all. Mr Trump’s unpredictability reflects on the entire situation.

The intervention of Rex Tillerson, who is among Trump’s more considered advisors, shows that the White House is still attempting to avoid all out escalation.

The danger depends in large part on whether those more sober heads can keep Mr Trump calm, and quiet. The former reality TV star’s statement isn’t as significant in what he said as that he was able and willing to say it at all. It introduces a new instability to an already fairly shaky situation, in the form of the most powerful man in the world.

Traditionally, North Korea has received help from countries like Russia and China. It might indeed be China that is at least partly motivating Mr Trump’s recent outburst – playing as it does to his campaign comments about re-negotiating the two countries’ relationship.

“I don’t think we’re seeing a US mobilisation for nuclear war,” said Mr Hannah.

"But Trump has invested himself heavily in the North Korea issue as an issue to prove himself.

“It’s also quite central to his approach to China. And China is a big part of his foreign policy, rhetorically at least.”

Very little, both in terms of the immediate danger and the knock-on diplomatic effects. European countries will obviously take a close interest in the latest developments, but they are relatively small players where such matters are concerned.

The US is involved because it has become a useful enemy for North Korea, for all sorts of reasons related to the Korean war and events before and since.

But the most important countries are generally those around North Korea, including Japan and South Korea – both of which are in easy reach of any weapons and are allies of the US – as well as Russia and China.

This could have all been prevented in the 1990s. Then, there was an appetite in North Korea for a negotiated solution, and a desire in the US to acquiesce.

Such a relatively straightforward solution may no longer be possible to fix a problem like Korea. The country believes, probably rightly, that its nuclear programme keeps other countries from launching regime change, meaning its leadership is unlikely to relinquish its huge, atomic bargaining chip.

So any security deal – bringing together all of the interested parties, including China, Russia and Japan as well as the US – would have to guarantee that there would be no regime change. That would be unpalatable to the US, since it would mean not only recognising but committing to perpetuate an oppressive and deadly regime.