Chances of second Korean War between 20 and 25 per cent
ANALYSIS: Having followed closely the events on the Korean Peninsula for the better part of 35 years, I believe the prospect of a second Korean War remains highly unlikely.
The reality is that it has now become an increasing possibility, but not a probability. Until recently most analysts would have regarded the prospect of a renewed conflict on the Korean Peninsula as a 5 per cent possibility. But because of a range of new factors, that possibility has now increased to between 20 and 25 per cent.
This reassessment has been driven by key advances in North Korea's capabilities - and the policy responses to these advances on the part of the US, China and the North Koreans themselves.
Chief among these technical advances is North Korea's purported recent testing of a hydrogen bomb.
* North Korea reportedly moves ICBM to coast
* UN diplomats call for more sanctions against North Korea following H-bomb test
* South Korea simulates attack after North's latest test
* US has options for North Korea's annihilation, James Mattis says
* US begins moving parts of THAAD anti-missile system into South Korea
There has also been a significant technical leap in the North's ballistic missile programme, it having demonstrated the ability to launch an intercontinental ballistic missile with the range to strike the continental US.
The fundamentals of the geopolitical landscape in our region, the East Asian hemisphere, have now changed.
The core reason for development of the North's missile and nuclear programmes is regime survival.
As much as Kim Jong-un might serve as a source of comic relief and caricature, he is not irrational or "crazy" as many would claim. He is a belligerent, dangerous, totalitarian leader - but one who is also providing what he concludes as the best guarantee of regime survival.
In China, there is a brutal assessment about how this is likely to play out.
China needs to be seen to be doing everything possible to pressure North Korea into action, both diplomatically and economically.
For China this would mean a halting of the North Korean ballistic missile and nuclear testing programme. But whatever pause or cessation of the programmes might be deliverable, the Chinese see little chance that North Koreans will scrap their nuclear bombs or ballistic missiles altogether.
The Chinese ultimately believe the US is going to have to live with North Korea as a nuclear weapons state.
China's object in the meantime is to convince the US and the wider international community that it is doing whatever it can to prevent that.
The Chinese military also believe that a North Korean nuclear capability is a nine-out-of-10 problem for America, and a one-out-of-10 problem for China.
So what are the possible scenarios?
One, that the US, as China would wish, informally accepts North Korea becoming part of the global nuclear weapons club, and that the North develops its own sets of rules, procedures and nuclear doctrine that enables it to behave "responsibly" as a nuclear weapons state.
Two, a US unilateral military strike to destroy or to retard the North Korean nuclear capability.
The conclusion in Beijing is that Washington would never risk the consequences for South Korea, Japan and the future of their alliances with both in such a way.
This is also the view held by many others in the wider region and around the world.
I'm less optimistic. Perhaps I've been in America too long.
As a colleague reminded me recently, war has its own logic. To which I would add, crises have their own logic. The best approach is to avoid crises in the first place.
Scenario three is diplomacy. But a potential diplomatic solution to this crisis does not appear to be going well so far.
There is also a broader proposition which goes by the name of the "grand bargain".
The reason why we need this is because there are fundamental interests at stake for China, for North Korea, for the US - indeed all of us.
What would this entail?
Beijing needs to accept the threat of a unilateral US strike is credible enough to warrant a change in Chinese diplomacy towards North Korea.
The US would need to be clear with Beijing about what is at stake here for China.
And if China succeeds in stopping and eradicating North Korea's nuclear programme, the US would then accept: a peace treaty to formally conclude the Korean War; diplomatic recognition of Pyongyang; security guarantees for the regime's future from the Chinese, Americans and possibly the Russians; further Chinese reform and development of the North's economy; and possibly - but most problematically - a step-by-step programme for the eventual withdrawal of US forces from South Korea.
In Washington there is an emerging discussion about the possibility of an American diplomatic initiative, which is to reach out directly to the North Koreans themselves.
That is gaining some currency.
What none of us know is what the content of such an initiative might be.
Such an approach would be a major departure from the previous US refusal to engage in direct bilateral talks with North Korea.
That view may be changing, contingent on certain conditions.
None of this would be easy.
A grand bargain here would go way beyond that which was agreed in the Iran nuclear deal. And this challenge is much more complicated, not least because the North's nuclear programme is much further developed.
We are living through a troubling and uncertain age.
But diplomacy is the only way to avoid a repeat of the tragedies of the 20th century.
History suggests our posture should be one of great caution.
- Kevin Rudd is the president of the Asia Society Policy Institute and a former prime minister of Australia.
- Sydney Morning Herald