This article was originally published by the Wall Street Journal.

This May, delegations from more than 180 countries gathered in New York, at the Nuclear Non-Proliferation Treaty Review Conference, to discuss how to free the world from nuclear weapons. Despite the positive momentum that flowed from President Barack Obama’s 2009 speech on the issue in Prague, there was enormous pressure on the conference. With a spirit of cooperation and flexibility from all delegates, however, the conference lived up to its expectations.

As foreign ministers, we draw two conclusions from this. First, it is remarkable that all delegates agreed on the conference’s action plan, which includes various new and important commitments on nuclear disarmament as well as concrete measures to implement the 1995 Middle East Resolution, which called for the a weapons of mass destruction-free zone in the region. We should do everything possible to implement this agreement.

Our second conclusion is that the agreement is extremely fragile.

Without an intensive concerted effort, states will not honor it. The irreconcilable views expressed throughout the conference-on such issues as the Iranian nuclear program and the Nuclear Non-Proliferation Treaty’s rules for how signatories withdraw-will not fade away.

ØPrior to the conference, major nuclear-weapons states took some remarkable steps. The U.S. and Russia agreed to further cut their strategic nuclear weapons. The U.S. also presented a new approach in its Nuclear Posture Review, published in April, which provided strong negative security assurances (that is, assurances that it would not use nuclear weapons against non-nuclear states).

We welcome and support the Obama administration’s commitment to achieving a world without nuclear weapons and strengthening nuclear security. Together with nuclear-weapons states, including the U.S., we are ready to discuss how to reduce the role of nuclear weapons-by, for example, committing to possess them only for the purpose of deterring others from using them. Even if nuclear states cannot immediately agree to abandon their nuclear weapons, they can take practical measures to reduce clear and present risks.

It is also necessary to make the possession of nuclear weapons unattractive. North Korea and Iran must understand that acquiring nuclear weapons in contradiction of their nonproliferation obligations would never be tolerated and would not elevate their status in the international community.

Like climate change, nuclear disarmament raises the question of whether mankind can feel a sense of responsibility across national borders and generations. Nuclear disarmament asks whether mankind can act to reduce the risks of self-destruction posed by “God’s fire.” We should never forget how human beings and buildings vanished in the tremendous flash of light and heat in Hiroshima and Nagasaki 65 years ago. This is a global issue that tests our sense of responsibility and morality.

Morality has recently played an important role in bringing about the success of treaties on land mines and cluster munitions. It is thus no coincidence that the Final Document of May’s conference cited the need for states to comply with international humanitarian law.

Some may ask themselves why Japan and Germany are seeking to pursue nuclear disarmament with such vigor when both countries rely on the United States for nuclear deterrence. Our countries have long been advocates of disarmament. Since re-emerging from total devastation in the second world war, both countries have pursued a peaceful and stable world and the total elimination of nuclear weapons. It is in such a shared conviction that we find a common role. And we believe that pursuing nuclear disarmament is the path that will most reliably minimize nuclear risks and enhance international security.

The 21st century will be about managing our planet. History will remember favorably those countries that respond with a sense of global responsibility. Let us set upon the realistic and responsible path towards a world without nuclear weapons. It is a moral responsibility.