Last night, President Donald Trump did what no other sitting U.S. president has done—he stepped foot onto North Korean soil and greeted North Korean chairman Kim Jong-un. And in typical Trump fashion, he staged a second dramatic crossing over the military demarcation line at Panmunjom with Kim, stepping together onto South Korean soil and greeting South Korean President Moon Jae-in before having a fifty-minute meeting in the South’s Freedom House.Leaving the DMZ, Trump said, “We moved mountains,” and that working-level talks led by U.S. special representative Stephen Biegun would get started right away. “The meeting was a very good one, very strong . . . We’re not looking for speed, we’re looking to get it right.”To get it right, the first step the Trump administration should take is to offer North Korea a security guarantee, whether in the form of an end of war declaration or a non-aggression pact. It may have been, after all, what convinced Kim to meet Trump at Panmunjom.One year ago, armed North and South Korean soldiers faced off. There were guard posts, landmines and speakers blasting propaganda across the DMZ. Today, the speakers and guard posts are down and many landmines were removed in the process of searching for the remains of U.S. soldiers who fell during the war. The fact that North Korean, South Korean and American security details could even stand side-by-side at Panmunjom is testament to the April 27, 2018 Panmunjom Summit where Moon and Kim announced to the world, “there will be no more war on the Korean Peninsula and thus a new era of peace has begun.” This agreement was the foundation for the Singapore Declaration, where Trump and Kim promised to establish new relations toward building a lasting peace and the denuclearization of the Korean Peninsula.