Earlier this week, the Department of Energy announced the major scientific accomplishment of achieving a fusion ignition in a lab setting. The experiment fired nearly two hundred high-power lasers at a small fuel pellet to briefly create the intense heat and pressure necessary for a fusion reaction to take place and, for the first time, the reaction produced more energy than it consumed.

A successful fusion ignition experiment is an important scientific achievement, but there are reasonable questions about the practical, near-term utility of the experiment.

The words “nuclear fusion” likely conjure images of space ships exploring distant galaxies or cities powered by nearly limitless clean energy. The latter point is especially salient as the United States and world contend with climate change. Commercially viable nuclear fusion could be a game changer for moving humanity away from fossil fuels.

Fusion as a source of energy was on the minds of many audience members during the Department of Energy’s press conference announcing the result of the ignition experiment. In fact, all the audience questions were related to the experiment’s energy implications and the scalability of the technology for commercial purposes. Unfortunately, fusion power plants remain in the realm of science fiction despite the recent experiment.

The outlook is better, however, for nuclear weapons.

The United States used to conduct explosive nuclear testing—detonating nuclear weapons underground, in the atmosphere, or underwater—to verify that the weapons would work as intended. However, the United States has not conducted an explosive nuclear test since September 1992. In 1996, the United States signed, but has not ratified, the Comprehensive Test Ban Treaty, an international agreement that prohibits explosive nuclear testing. Except for North Korea, no other country has conducted an explosive test since 1998.

Since the 1990s, the United States has maintained the reliability of its nuclear forces through the “stockpile stewardship program,” which uses a variety of scientific instruments and experiments to simulate how nuclear weapons would perform without detonating them. Stockpile stewardship allows the United States to keep its nuclear arsenal in working condition while maintaining the international norm of not carrying out a nuclear explosion. The National Ignition Facility (NIF) that conducted the recent successful fusion experiment is part of the stockpile stewardship program. Specifically, the NIF creates fusion reactions that imitate some of the conditions that exist in a nuclear explosion at a much smaller and contained scale to test how warhead components react to those conditions.

The United States has a very large nuclear weapons inventory. In May 2022, researchers at the Federation of American Scientists estimated a total nuclear weapons inventory of approximately 5,400 warheads (1,744 deployed, 1,964 in reserve, 1,720 awaiting dismantlement). The United States is also undertaking a major nuclear modernization effort that includes updates to existing weapons designs, new delivery platforms, and new warheads.

The recent fusion ignition experiment comes at a critical time for nuclear stability. Russia’s nuclear threats made during the invasion of Ukraine, China’s steadily growing nuclear arsenal, and a recent acceleration in North Korea’s missile testing are raising concerns about a more dangerous nuclear future. A 2020 report by the Washington Post stated that the Trump administration discussed whether to resume explosive nuclear testing as part of an effort to push China and Russia into an arms control agreement with the United States. If nuclear dangers continue to grow, calls for a return to explosive testing will likely grow louder and more urgent.

A scientific breakthrough at the NIF provides a valuable retort to arguments in favor of resuming explosive nuclear testing. The more guardrails in place to prevent destabilizing activities like nuclear tests the better, especially given the Trump administration’s hollowing out of arms control agreements.

Nuclear fusion power plants remain a dream of the distant future. Preventing a new nuclear arms race will help us reach that future. The NIF’s latest fusion experiment will help, in a small way, to avoid near term calamity so we can get to a future where science fiction becomes reality.