The developments regarding Korea this week are astonishing. We may be witnessing a breathtaking outbreak of peace, when not very long ago a nuclear war seemed possible.

Now that the Koreas have gotten the diplomatic ball rolling, can President Donald Trump do his part?

For Trump’s planned meeting with Kim Jong-un, announced at the White House by South Korea’s security director Chung Eui-yong, to be successful, the administration will need to do a lot more diplomatic leg work than it’s used to. It will also be important to set expectations appropriately — we can’t expect one meeting between the two leaders to end in a comprehensive agreement like the Iran nuclear accord, which took years to negotiate. But challenges aside, it’s hard to imagine how Trump could scuttle this progress, short of calling off the meeting or throwing in the towel at the first disagreement and pivoting back toward threats of war.

Now South Korea, with its right-wing opposition to budding Nobel Peace Prize candidate President Moon Jae-in, or North Korea, with its unpredictable leader Kim Jong-un, could well mess things up on their own, so the extremely hopeful thaw in relations brought about by the Olympic Truce is far from a done deal.

However, it seems North Korea has put so much on the table, probably more than President Moon could have asked for, that there should be no going back.

And for his part, Trump already made one wise decision, agreeing to President Moon’s request to postpone the massive U.S.-South Korea military exercises after the conclusion of the Paralympics in South Korea in late March. Now that Pyongyang accepts that the exercises will proceed next month (an astonishing concession given North Korea’s legitimate security concerns in relation to the war games), Trump has the chance to do what no president has done in seven decades—help achieve lasting peace on the Korean Peninsula.

The North, for its part, has already helped set the stage for productive dialogue with a host of concessions, including committing not to test nuclear weapons or ballistic missiles while talks are ongoing, accepting that the U.S.-South Korean war games will continue, and committing not to attack South Korea. Beyond concessions, North Korea has expressed a desire for normalized relations with the U.S. and South Korea, and a willingness to denuclearize if its security concerns are adequately addressed, a reiteration of a longstanding position. These impressive concessions and gestures of good faith offer propitious grounds for negotiations. Trump needs to take them seriously, understand the gravity of the opportunity, and act accordingly.

It makes sense for Moon, who was elected on a platform of reviving the sunshine policy with the North (in which he participated in earlier governments), to take the lead. It’s the Korean Peninsula, not Florida or Cape Cod. Koreans need to be allowed to make peace, regardless of the interests of outside powers. Ultimately though, if the long-term goal of negotiations is a peace treaty, a goal shared by both Koreas, then the U.S. will need to do more than just stay out of the way. But the task before President Trump right now is continuing in the right direction, and that means following Moon’s lead.

Some have feared Trump could launch a war to distract from his peccadilloes and attempt to raise his dismal poll numbers, counting on a “rally round the flag and president” effect. While not unfounded, it would seem that would be too outrageous, even for Trump, when peace appears to be so close at hand. Indeed, he could gain more politically by supporting a peace deal on the Korean Peninsula than by starting yet another war, which would be a catastrophe, and getting the U.S. into more wars was something he campaigned against.

So let’s take counsel of our hopes, not our fears, and let 2018 be the year the Korean War was really ended, for good.

Kevin Martin, syndicated by PeaceVoice, is President of Peace Action, the country’s largest grassroots peace and disarmament organization with more than 200,000 supporters nationwide, and he convenes the Korea Peace Network, a network of peace, arms control, and Korean-American activists working for peace on the Korean Peninsula.