KIM JONG-UN: MASTER PUPPETEER

The North Korean leader wants to achieve what his father and grandfather never could - a meeting with the US president which would, in his eyes, cement his legitimacy. But what will also secure his legacy is the economic development his country desperately needs and Kim has his eye on that prize too. To achieve this long-held desire he has dramatically shifted in character from isolated angry strongman to international statesman. After months of fiery rhetoric and steady nuclear progress, the North Korean leader used a speech at New Year to open the door to dialogue with the South. Relations warmed rapidly, hitting a crescendo soon after with the first meeting of Korean leaders in more than decade. Throughout he has controlled the spectacle. The young leader has been swept to centre stage by two new props: his unprecedented nuclear capability and an unconventional US president. And by exploiting that serendipity, he has brought the US to the table. 

DONALD TRUMP: THE ULTIMATE DEALMAKER

Trump has positioned himself as the only one who could make progress on the North Korean threat, and in so doing, declared world peace within reach. He says it is his "maximum pressure" approach that enabled a breakthrough that his successors could not. Never straying from the Art of the Deal, Trump said he would leave the meeting if he didn't like where it was heading. Trump was able to portray North Korea's scramble to convince him to stay in the talks as a victory - but also to redefine the terms of the talks. It gave him room to move from demanding North Korea totally give up its nuclear weapons to accepting that could be a phased process. Poll numbers that showed most Americans - on both sides of the aisle - approve of his handling of North Korea.

XI JINPING: THE HIDDEN PLAYER

The Chinese leader's role is the most opaque. China - North Korea's only ally - has long pushed for dialogue between Washington and Pyongyang. When Kim first emerged from international isolation this year it was for a secret meeting with Xi Jinping. A second trip followed soon after. Speculation swirled over whether that discussion had steeled North Korea to take a firmer line with the US. One week after the leaders smiled over tea in Dalian, Pyongyang returned to old form, lobbing blistering attacks at the US. Donald Trump himself raised suspicions that a visit to China had sparked Kim's change in tone. Beijing wants the summit, says Yun Sun, director of the China program at the Stimson Centre. Exactly what hand Xi is playing isn't clear. What is clear is that it was only once China threw its weight behind economic sanctions that North Korea started talking.