STOCKHOLM/MEXICO CITY ― Indonesia’s parliament has just taken a historic step, one that makes the planet safer from the threat of nuclear weapons. The importance of Indonesia’s decision to ratify the Comprehensive Nuclear-Test-Ban Treaty cannot be overstated. This is a golden opportunity for the remaining eight countries to endorse the CTBT, enabling it to come into legal effect.

For the five decades following World War II, a nuclear test shook and irradiated the planet on average every nine days. This era was ended in 1996, when the Comprehensive Nuclear-Test-Ban Treaty was adopted by the United Nations General Assembly. But, for the CTBT to enter into force, all 44 states specified as holders of nuclear technology must ratify it. Until they do, the specter of nuclear testing will continue to haunt us.

It is urgent that the CTBT take full legal effect around the world as soon as possible. A complete ban on all nuclear explosions would hamper the upgrading of existing nuclear arsenals and the development of new weapons, diminishing the capabilities of both current and potential nuclear-armed states. The CTBT reinforces both nuclear non-proliferation and nuclear disarmament, and is essential for global, regional, and national security.

We applaud the fact that all of the nuclear-capable countries in Europe and Latin America and many in other regions in the world have ratified the CTBT. With Indonesia’s ratification, the number of countries that have yet to do so has decreased to eight: China, Egypt, India, Iran, Israel, Pakistan, North Korea, and the United States. These countries have a responsibility to make the legal ban on nuclear testing a reality. We strongly urge them to reconsider the CTBT; this important instrument for peace and security will bring us a step closer to a world without the threat of nuclear weapons.

The CTBT has already had a dramatic impact, despite not yet being in force. Since its adoption, nuclear testing has virtually stopped, and all 182 signatory states have abstained from testing nuclear explosives. The three countries that have failed to ratify the CTBT and have tested such devices ― India, Pakistan, and North Korea ― have faced universal condemnation from the U.N. Security Council, and U.N. sanctions.

A key measure of the viability of any arms-control treaty is how effectively it can be verified. In this respect, the international community has a formidable instrument at its disposal. The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is creating a verification regime that has repeatedly proven its reliability in detecting even small underground nuclear tests.

In addition to its verification mandate, the CTBT monitoring system also helps to mitigate disasters. During the tragic catastrophe in Japan last March, CTBTO data helped local authorities to issue timely alerts. The CTBTO continued to help by monitoring the global dispersion of radioactivity from the damaged Fukushima nuclear power plant.

Mexico and Sweden are longstanding supporters of the CTBT. Over the coming two years, our countries will jointly oversee the process of bringing the CTBT into force. We pledge to spare no effort to advance this aim. We vow to:

― Call upon political leaders in the states that have not yet ratified the CTBT to act without delay and take concrete steps to this end;

― Encourage civil-society groups ― NGOs, media, universities, and youth organizations ― in these countries to urge their decision-makers to ratify the CTBT;

― Use national, regional, and international meetings and conferences to promote the CTBT at every level of decision-making;

― Complete the CTBTO’s verification regime, which all states should support as a powerful deterrent to any would-be nuclear testers.

It is time to end this destructive experiment and close the door on nuclear testing once and for all. We appeal to decision-makers in the eight states that have not yet ratified the CTBT to move forward. Indonesia has set an example; now the spotlight is on you.

By Carl Bildt and Patricia Espinosa Cantellano

Carl Bildt is foreign minister of Sweden. Patricia Espinosa Cantellano is foreign minister of Mexico. ― Ed.

(Project Syndicate)