As world leaders convene in Washington this week to discuss nuclearâ??terrorism prevention, South Korea’s president, Park Guen-hye, is likely to receive special attention. That’s because her country is roiling with internal pressure to build nuclear weapons.

South Korea today is a global leader in the peaceful use of nuclear energy. It regained international trust over decades, after disclosing past nuclear weapons-related research it conducted in secret. It hosted the Nuclear Security Summit in 2012, and will co-chair the International Atomic Energy Agency’s nuclear security meeting this December.

But South Korea’s leadership and reputation on nuclear security are again at stake.

Following North Korea’s fourth nuclear test in January, South Korea’s ruling party leaders, politicians, pundits, and its main newspaper, The Chosun Ilbo, all called for South Korea to acquire nuclear arms to defend itself. A recent poll by the newspaper Joong Ang Ilbo found that two-thirds of South Koreans supported nuclear armament. Some politicians are even advocating withdrawal from the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), because of jeopardy to South Korea’s supreme national interests. That would mean South Korea’s failure to abide by a key piece of the international security regime controlling nuclear weapons.

It would be a mistake, and a danger to the region, for South Korea to acquire nuclear weapons. But should it seek to do so, those who are intent on opposing Seoul would do well to remember how that country went about its secret attempts to acquire such weapons decades ago. In 1970, the U.S. announced plans to withdraw part of its military forces stationed in South Korea, and began doing so. This shocked the South Korean government, which immediately established an agency to develop nuclear weapons—the Agency for Defense Development. It also created the Weapons Exploitation Committee. South Korea sought fissile material to create its nuclear arsenal. In the early to mid-1970s it tried to purchase a spent nuclear fuel reprocessing plant from France. The South Korean government also approached Canada and Belgium. These efforts to acquire fissile material ultimately failed, due in part to United States pressure. This clandestine nuclear weapons effort by the South Korean government likely ended in October 1979, after the assassination of President Park Chung-Hee, father of the current President.

Still, sensitive research continued quietly on a smaller scale at the national lab, Korea Atomic Energy Research Institute (KAERI), including separating small quantities of plutonium from spent nuclear fuel and enriching uranium using lasers. In 2004, in its reporting to the International Atomic Energy Agency (IAEA), South Korea publicly disclosed these past nuclear weapons-related research activities, which violated its international agreements.

Since then, South Korea has tried to increase the transparency of its nuclear energy generation and nuclear power research and development. The IAEA has deemed past violations resolved. Today, South Korea has 24 operating power reactors that provide about one third of its electricity, and its nuclear capacity is expected to double by 2035. It has also emerged as a nuclear exporter. The United Arab Emirates (UAE) ordered four of its nuclear power plants in 2009.

It has taken years for South Korea to build this credibility and demonstrate its commitment to the peaceful use of nuclear energy and nuclear nonproliferation. Today, it is a global leader in the industry.

Losing that trust would only take a moment.

Last month, South Korean Prime Minister Hwang Kyo-ahn said the country will maintain its denuclearization policy. But the government’s messages are mixed. Junghoon Kim, the ruling party’s chief policymaker, said, “South Korea should at least have capability to make nuclear weapons anytime to countermeasure North Korea’s nuclear weapons … South Korea should reprocess its spent fuel.”

Nuclear armament of South Korea would provoke an arms race in Northeast Asia that would be almost impossible to stop. It would risk a nuclear war between the two Koreas that could involve China, Japan and the United States. The South Korean government should aggressively denounce calls for making nuclear weapons. It should be vigilant in keeping its nuclear energy program peaceful—and distinct from—fissile materials production for nuclear weapons development.