Nuclear stand-offs are nothing new. It was during one of the most serious, the Cuban Missile Crisis in 1962 between the US and Soviet Union, that the then two leaders of those countries, President John F Kennedy and Premier Nikita Khrushchev had one of their famous political exchanges.

“We and you ought not now to pull on the ends of the rope in which you have tied the knot of war, because the more the two of us pull, the tighter that knot will be tied,” Khrushchev warned Kennedy at the height of the crisis.

Tense as those days were back during the Cold War, the language between the two men, though often uncompromising, almost always had a considered and eventually conciliatory tone, much to the relief of the world.

Both Kennedy and Khrushchev had of course experienced the horrors of conflict first hand, serving their countries during the Second World War.

The same cannot be said of their contemporary counterparts, President Donald Trump and North Korean leader Kim Jong-Un, who in the last few days have escalated the war of words between them over the nuclear crisis in the Korean Peninsula to alarming levels.

While Trump threatens to unleash “fire and fury” and says America is “locked and loaded,” Kim in the past has himself talked of reducing “all bases of provocations” to “flames and ashes”.

Such now is the bellicosity of the rhetoric between the two leaders, that only yesterday China’s president Xi Jinping urged both men to avoid “words and actions” that worsen tensions.

As crucial a political and diplomatic player as China is in all of this, Xi’s words may well fall on deaf ears given the character of the two men.

Both have been described as moody, capricious and prone to childish outbursts when things don’t go their way. Something the world has witnessed for itself in Trump’s case on numerous occasions already.

One US Republican political commentator, Anna Navarro, said Trump’s handling of the North Korean crisis is “like he’s playing Battleship in between golf games.”

Her remarks were underlined by the fact that Trump this weekend delivered his latest verbal blast towards Pyongyang from his Bedminister, New Jersey golf resort. The crisis, it seems, has done little to interfere with his penchant for retreating at weekends to various golf resorts.

Such behaviour however belies the seriousness of the stand-off with North Korea, one that has been heading steadily on a collision course for some time.

Given the point at which this crisis now sits, just how then did the situation get this tense, and is nuclear war really a possibility or will events unfold differently?

The United States and North Korea have of course been in conflict for decades. The development of the North’s nuclear weapons programme has only intensified the enmity between the two countries. What is no longer in doubt is that while the North has conducted several tests with nuclear bombs, there remains some uncertainty over whether it has the capacity to make a nuclear warhead small enough to fit on to a missile.

Last year Pyongyang released a photograph of its leader, Kim Jong-Un posing with what appeared to be a miniaturised nuclear warhead.

According to conclusions drawn by some US intelligence officials the bomb that was about two feet in diameter, with a destructive yield equivalent to the atomic bombs that the US dropped on Japan in World War II, could be carried by a long-range missile.

US intelligence officials now say they believe North Korea is capable of miniaturisation, even if some international experts have long cast doubt on such claims.

What has been long established though is that the North has been steadily building and testing such missiles.

“There is little doubt that it has some current nuclear strike capability with air delivered weapons and may already have a marginal capability to deliver missiles with nuclear warheads against city-sized targets in South Korea and Japan,” says Anthony H. Cordesman, Chair in Strategy at the Centre for Strategic and International Studies (CSIS).

According to Cordesman, the North is also only perhaps months to years away from developing a “reasonable probability of delivering a moderate fission-sized weapon against an American city with a high chance of success.”

That probability was made all the more likely with the test firing early last month of an intercontinental ballistic missile (ICBM) officials said was capable of hitting Alaska and Hawaii.

A few weeks later the North tested another missile which experts said was capable of hitting California. In response, the US decided the time had come to toughen its military stance.

As tensions spiked last Tuesday with Trump threatening to meet any aggression from Pyongyang with “fire and fury like the world has never seen,” Kim responded in equally apocalyptic tones.

Insisting it would create “an enveloping fire” around Guam, a tiny American territory in the Western Pacific that is home to a US Air Force base, the north then announced in was preparing plans to fire four ballistic missiles near to Guam.

According to comments attributed to General Kim Rak Gyon, commander of the Strategic Force of the Korean People’s Army, the military is drawing up plans for a four-missile salvo of Hwasong-12 intermediate ballistic missiles to fly over Japan and land about 18-25 miles from Guam.

Once prepared the plan will be presented to North Korean leader Kim Jong Un by the middle of this month, after which Pyongyang will “keep closely watching the speech and behaviour of the US.”

There are a number of crucial factors that need to be borne in mind with regard to these comments from the North.

The first is that they come just ahead of the annual large scale Ulchi Freedom Guardian military exercises between South Korea and the US, which begin at the end of August.

The second is that such comments by the North of drawing up operational plans during times of heightened tension is not unusual in itself. The comments are, according to assessments by the US open intelligence monitoring group Stratfor, clearly conditional threats.

This is emphasised by Pyongyang’s assertion that the US “should immediately stop its reckless military provocation against (North Korea) so that the latter would not be forced to make an unavoidable military choice.”

During the current round of heated language it’s important to recognise the real wording being played out away from the more lurid apocalyptic headlines. It could very well be that the North is simply looking to bring pressure on the US and South Korea to halt their annual military exercises.

The practicalities to the Guam operation it boasts of launching are also worth considering in more realistic detail too. While it talks of the Hwasong-12 missiles hitting the waters18-25 miles from Guam, the reality is that the missile itself has only ever had a single successful launch after a series of back-to-back tests earlier this year. In other words it’s not clear if the missile is reliable enough for the North to make its point even if it thought it was necessary to do so.

That said, it would be very wrong to assume that the North is all about bluster or that the already tense stand-off might not still deteriorate to the worst possible scenario of all out confrontation or nuclear war.

Not only is North Korea the most militarised nation in the world, but no one can count on its dictator showing restraint.

Should war break out then in conventional terms the North though possessing large air and missile forces, lags way behind the capacity of South Korea and the US.

As Anthony H. Cordesman, of CSIS points out, North Korea has no stealth capability, and most of its missiles have limited accuracy and lethality against critical military and infrastructure targets if they are used with conventional warheads.

By comparison South Korea now has precision guided missiles of its own, and the US can deploy large numbers of cruise missiles and air-launched precision-guided systems.

“North Korea has enough ground power to pose a serious threat and the initial phase of any serious war would cost South Korea a great deal,” says Cordesman.

“Unless China came to its aid, [the North] could not come close to the initial advances it made in the Korean War. It would take massive losses in any intense fighting, and it would lose over time,” adds Cordesman. While the tension continues, behind the scenes, however, it’s not clear that a major military confrontation is indeed imminent.

Many analysts point to the fact that Trump’s sharp rhetoric is belied by the business-as-usual routines of the US Defence Department. For decades the US military has been on stand-by for a belligerent act from North Korea, a readiness summed up by the motto of US Army’s Second Infantry Division, based in South Korea: “Ready to fight tonight.”

“There’s always some degree of readiness, but in the face of these indications and warnings that North Korea is communicating deliberately, we’re going to no doubt have an even higher condition of readiness,” says Thomas Karako, a senior fellow at CSIS in Washington.

So what should we be watching for to help understand the direction in which this crisis might be heading?

At a purely ground level, analysts point to some telling signs that would indicate conflict was on the horizon. One of these would be the drawdown of non-essential US personnel in South Korea. Most certainly we would see on a voluntary or mandatory basis the departure of family members of US military and diplomatic personnel.

Such a move would be a clear indicator of impending conflict particularly because Seoul, the South Korean capital and most populous city, sits just 35 miles south of the border separating it from the North.

Aircraft deployments too might send out a warning of war. When Trump tweeted out a series of photos of long-range B-1B bombers at Andersen Air Force base in Guam a few days ago his intention was obvious.

These bombers have long been a key tool in the US arsenal for any renewed conflict in Korea, replacing the B-52 bombers used in earlier decades.

“More aircraft deployments, particularly bombers to Andersen in Guam and perhaps Hickam in Hawaii,” would be sign conflict is coming, says Rob Levinson, a senior defence analyst.

Likewise naval and ship deployments would suggest the same. The movement of ships towards Korea especially the six US Navy vessels capable of defending against ballistic missiles, that are normally based at Yokosuka, on the eastern side of Japan, would signal that potential action to stop a missile launch is more imminent. It would also likely be seen by Pyongyang as an urgent threat.

In any crisis such as that currently unfolding in the Korean peninsula, nations so often have a hard time reading one another’s internal politics, so they tend to rely heavily on reading one another’s actions for clues as to their intentions.

As Max Fisher writing in the New York Times a few days ago rightly pointed out “current American action, or lack thereof, sends a message of calm and caution, rather than “fire and fury.”

If US troops remain in barracks in nearby Japan and Guam and warships keep their distance, these are the sorts of signals - rather than a leader's offhand comments or Tweets - that matter most in international relations.

The lack of incentive to escalate, and a mutual understanding that no one stands to gain from all out confrontation, are also key restraining factors right now.

Donald Trump and Kim Jong-Un would do well to look back on that political exchange that occurred between John F Kennedy and Nikita Khrushchev during the Cuban Missile Crisis of 1962. They should reflect too on the implications of pulling on both ends of that rope in which the knot of war is tied.

As Khrushchev summed it up: “A moment may come when that knot will be tied so tight that even he who tied it will not have the strength to untie it, and then it will be necessary to cut that knot, and what that would mean is not for me to explain to you, because you yourself understand perfectly of what terrible forces our countries dispose.”