Editor's Note: (Beatrice Fihn is executive director of ICAN, winners of the 2017 Nobel Peace Prize. The opinions in this article belong to the author. )

(CNN) The world could only sit passively by this week as two men toyed with the fate of humanity, on the flawed assumption that Donald Trump and Kim Jong Un had our collective best interests at heart.

President Trump is showing us the dangers of placing our lives in the hands of a couple of fragile men. In this month alone, he has torpedoed the successful Iran nuclear deal and sunk our best hope of North Korea engaging in direct diplomacy as a means to denuclearize.

On Thursday, he threatened mass murder of millions of innocent civilians while pulling out of the upcoming summit with Kim Jong Un for reasons of hurt feelings and strong language.

Does anyone feel safer now?

But that is the lie nuclear states have been telling us for 70 years: We are safest living a breath away from annihilation because there are "good guys" with a nuclear weapon (Trump), who will discourage 'bad guys' from ever wanting them (Kim). Sound familiar?

In reality, the greatest threat we face is the existence of nuclear weapons in the first place. Just ask South Korean President Moon Jae-In. He lives within range of conventional weapons permanently aimed at Seoul that can be launched before US nuclear weapons destroy the North Korean regime.

There is no military scenario where tens of thousands of South Koreans don't die within the first minutes of any conflict.

Knowing this, his worst nightmare came true this year with Trump's war of words that pushed us to the brink of nuclear destruction. His solution? Careful diplomacy with the North on one hand, and gentle ego stroking of Trump on the other hand (Nobel prize, anyone?).

By playing to the man's ego, Moon convinced Trump to try statesman-like diplomacy and brought North Korea on board with denuclearization.

And just for a moment, the world clung to hope it would work. Early Thursday morning, North Korea, largely in a symbolic gesture, put on a show by blowing up their nuclear test site. Trump responded by blowing up the peace process.

All of this goes to show we cannot rely on these piecemeal agreements on nuclear weapons to guarantee our safety. Men with fragile egos should not have the world's faith placed in them to solve these existential crises.

Instead, we already have a solution. These weapons are now prohibited by treaty, and it is a matter of getting every state on board. Last year 122 nations adopted the UN Treaty on the Prohibition of Nuclear Weapons at the UN, and it is well on its way to becoming international law.

Quite simply, the possession of nuclear weapons by anyone is a grave humanitarian threat that we cannot countenance. South Koreans should not have to go to bed at night wondering if a Tweet sent from across the Pacific will mean they won't wake up in the morning.

There is still hope for the Koreas. We've been accused by Trump of clinging to a magical vision of a nuclear free world. But this episode demonstrates we are the realistic ones, we have the legitimate path forward to denuclearization using a multilateral treaty that can't be torn up if someone's feelings are hurt.