Peace in the Korean peninsula has edged a little closer this week with the third meeting since April between the presidents of North and South Korea. Seoul’s Moon Jae-in went to Pyongyang for further talks with Kim Jong-un and it appears that they have made progress. Moon announced the main advance — he in fact called it “ a leap forward” — was that international inspectors would be able to verify that the North has dismantled its main missile testing and launch site at Tongchang-ri.

This, said Moon, was part of an agreed route to achieve denuclearization. But his opposite number has already made clear that the next step in the process, the shutting down on the key Yongbyon nuclear facility, is dependent on the US taking “reciprocal action”. This has not yet been spelt out but Kim is doubtless thinking of the battlefield nuclear weapons which the 23,000 American troops still based in the South are assumed to have deployed.

This is Washington’s big stick, which would be used to devastating effect if Pyongyang launched its one million strong army against the South Koreans who have half as many troops. When Donald Trump met Kim in June he will have seen up close the paranoia, which has guided the three generations of Kim family dictators since the end of three years of fighting in the peninsula in 1953. That paranoia has been used to create the “Hermit Kingdom”, a highly-regimented society where every citizen is taught they are under constant threat from an aggressive South and its US ally. Pyongyang’s acquisition of nuclear weaponry and the missiles to deliver them, seemingly even to the West Coast of the United States, was, for the regime, the ultimate deterrent against attack.

So Kim Jong-un is now in a poker game where the protection and security of his dictatorship must be secured even as he abandons his nuclear shield. It is clear that he has only come to this point because it is willed by his key ally in Beijing, whose economic and financial support is essential. But Beijing cannot not wish to see a US diplomatic triumph, which will continue to embed American troops in South Korea. The Chinese leadership wants the process that Trump began, seemingly against all the odds, to end with Washington’s disengagement from the South. Thus it is almost certainly encouraging the negotiations to pass more firmly into the hands of the two Korean presidents. A lasting North-South reconciliation, even with a long-term program for actual reunion, might be nearing the table, very likely with an exclusive security guarantee from Beijing.

If the Trump administration has foreseen this possibility or the Pentagon’s planners are independently trying to figure out how to handle such an outcome, there is one potential hurdle to be crossed, which would require Washington’s agreement, as a member of the UN. North Korea is still officially at war with the United Nations because it was only an armistice that was signed in July 1953. In terms of international law, rapprochement between North and South Korea cannot go ahead without a formal peace agreement to end a war, which has officially been going on for 68 years. And perhaps bizarrely, the South Koreans would not be primary signatories since the armistice with the North was inked by the UN.