(CNN)In 2017, the idea of Kim Jong Un meeting with US President Donald Trump and South Korea's Moon Jae-in would've been unthinkable.
Korean summit: How we got here
North Korea test-fired more than 20 missiles, including three it claimed were capable of reaching the United States, and their most powerful nuclear weapon to date. Experts said the Kim regime was dangerously close to developing the capability to hit major US cities with a nuclear weapon, if it didn't have it already.
However, the winds shifted in 2018 beginning with Kim's New Year speech, in which he wished his southern neighbors good luck in hosting the Winter Olympics in Pyeongchang.
President Moon took that olive branch and ran with it, inviting North Korea to attend and participate in the Games.
Here's how the diplomatic rapprochement unfolded.