President Donald Trump's now highly likely meeting with North Korean leader Kim Jong Un on June 12 in Singapore could play out in a number of ways, say Korea analysts.
The most probable outcome is an immediate gesture, possibly shipping a few intercontinental ballistic missiles from North Korea to the US.
This would be followed by a phased reduction of North Korea's nuclear arsenal, which experts say will take anything from five to 15 years, although it would likely continue to have some weapons of mass destruction for some years.
In return for such a "front-loaded" deal, North Korea would get security guarantees and calibrated economic incentives from the US and its allies. Analysts brand this a "good-bad scenario" - a quick win, but with details left to be thrashed out.
A second possible scenario would be simply bad - a breakdown of talks and a continuation of the US and global community's "maximum pressure" campaign on North Korea. A third scenario would be catastrophe - a quick and acrimonious breakdown, with Mr Trump walking out and, possibly, even US strikes on North Korea.
Former British foreign secretary William Hague wrote in The Telegraph this week that the first possibility is that the talks end in acrimony as Mr Kim's offer would not be good enough.
The North Korean leader can then say he did his best. He would have driven a wedge between the US-South Korea alliance, kept his warheads and been able to blame Mr Trump while relying on China to relax the imposition of sanctions.
A second possibility, Mr Hague wrote, is a staggered agreement which leaves the US feeling safer but regional allies like Japan still within range of Mr Kim's missiles.
Or Mr Kim agrees to dismantle his nuclear weapons if a peace treaty ends the Korean War and American forces in the South leave.
Luckily, given that both leaders appear highly invested in the process, both need to come out looking good. American analysts believe the "good-bad" scenario is therefore the most likely.
"Kim Jong Un knows what Trump wants," said Dr Sue Mi Terry, a former Korea analyst with the CIA and senior fellow, Korea chair, at the Centre for Strategic and International Studies.
Mr Trump has mid-term congressional elections looming in November. He is hampered by opposition at home on big policy issues but has more unilateral authority in foreign policy, so a big win would come in handy.
Mr Frank Jannuzi, president and chief executive of the Mansfield Foundation, said at the Stimson Centre think-tank that the two leaders will likely "agree to basic principles - denuclearisation and peace hand in hand in some kind of phased reciprocal plan of action".
"But the end goal will be clear - Kim Jong Un will promise denuclearisation, and President Trump will promise peace," added Mr Jannuzi, who has advised the Senate Foreign Relations Committee. "I think we will get that outcome. It is a bad outcome because none of the denuclearisation details is going to be agreed, not even the definition of denuclearisation. But it will set in motion a process... a difficult negotiation that hopefully will bear fruit."
Nuclear experts Siegfried Hecker, Robert Carlin and Elliot Serbin wrote in a Stanford University paper this week that a "halt, roll back and eliminate" phased approach over a decade or so will be required to denuclearise North Korea because of the enormity of its nuclear weapons enterprise and the huge trust deficit between Washington and Pyongyang.
There may be another, more out-of-the-box scenario, which some South Korean academics have entertained: North Korea signs up to a grand deal with the US providing it a security guarantee in the form of its nuclear umbrella. This would be a geopolitical paradigm shift in the region.
But North Korea will be making its own strategic calculations.
"It is a bold idea," said Dr Terry. "But North Korea has China on its doorstep, and does not trust the United States. And we have President Xi Jinping whispering sweet nothings into Kim Jong Un's ear. China needs to continue to wield influence over North Korea."
