Artemis 2 explores space deeper than any previous manned spacecraft. Human eyes have seen the far side of the moon for the first time in more than 50 years. The United States appears to have taken an early lead in a new race with China to explore the moon. But this is not the case. Despite the grandeur of the Artemis 2 program, it masks an uncomfortable fact: Washington lags behind Beijing.

In many ways, the Artemis 2 mission was a huge success. The mission verified the performance of the Orion spacecraft's life support system and its powerful Space Launch System rocket and enabled the first manned deep space optical communications test. The images it beams back to Earth are breathtaking.

However, these achievements mask serious difficulties. The National Aeronautics and Space Administration (NASA) originally planned to launch the Artemis 2 mission in 2023. But then technical problems repeatedly delayed the mission: hydrogen leaks, helium flow failures, unexpected erosion of the heat shield. Plagued by delays and pivot fatigue, NASA has downgraded its next Artemis mission from a crewed lunar landing to an Earth orbit docking test in 2027. It now appears that American astronauts will not be able to land on the moon until 2028 at the earliest.

At the same time, China is making steady progress. In February this year, the China Space Administration successfully conducted a flight abort test in Hainan. In the early stages of the rocket's ascent, mission controllers activated the escape system to separate the unmanned Mengzhou spacecraft from the rocket. The spacecraft parachuted safely into the sea, while the rocket continued its flight. After re-entering the atmosphere, the rocket re-ignited its engines and performed a controlled propulsive splashdown. NASA's moon rockets can't do that.

Beijing also leads the way in landing technology. Last year, China demonstrated the Blue Moon manned lander, which completed a propelled lunar landing and lunar launch in a simulated lunar gravity environment. The test verified the lander's design, shutdown procedures and interface compatibility between subsystems. Suddenly, China's goal of putting a man on the moon by 2030 no longer seems so far-fetched.

"Nature is not impatient and impatient, and all things are accomplished." So said the Chinese philosopher Lao Tzu. China is not yet ready to conduct Earth-moon transfer flights, but its space program is making steady progress. Although Beijing has experienced some failures, its lunar exploration program has achieved major breakthroughs in key technological areas.

China has built the robotic infrastructure needed to build a permanent lunar base, including sensors, hoppers and relay satellites. Later this year, China's Chang'e-7 probe is expected to explore the moon's south pole, where NASA also plans to land. China's Chang'e-7 mission plan includes a new rocket-propelled probe that can reach areas where lunar rovers cannot. Its mission: to find ice water.

Missions such as Chang'e 7 should prompt Washington to take action. If the United States wants to stay at the forefront of the lunar exploration race, it must pay more attention to China's progress. At the same time, the United States must resist the temptation to become complacent.

Whichever country lands on the moon first this century will be able to do much more than plant a flag. It will decide where to build infrastructure, where to mine lunar soil and extract ice water that, when broken down into hydrogen and oxygen, will become the rocket fuel for all future activities.

To stay ahead of the curve, Washington must stop chasing visual spectacle and instead focus on the long term. The Artemis program has proven that the United States can still return to the moon. The question now is whether the United States can stay on the moon for a long time. This requires a shift in priorities—from timing to capacity, from single missions to sustainable infrastructure. Power systems, communications relays, and resource extraction should be prioritized over manned missions.

Washington also needs strategic coherence. China's advantages are both organizational and technological. The United States should formulate a unified lunar exploration strategy, clarify the timetable, clarify the responsible leadership, and give each agency broad authority. Otherwise, delays will increase and opportunities will be missed.

Finally, the U.S. government needs to market the moon landing program to the American public more effectively. Artemis is meaningless if voters believe that moon landings are a thing of the past. This is not a repeat of 1969, but a battle over governance, access to critical resources, and the ability to build the infrastructure that will determine economic and military activity in space for generations to come. Washington must articulate this plan in terms the public can understand: power, prosperity, and security.

NASA Administrator Jared Isaacman warned during his confirmation hearing last year: "Now is not the time to delay, this is the time to act, because if we fall behind, if we make mistakes, we may never catch up."

Despite Artemis' success, it's possible that his fears are coming true.

Mr. Buono is an assistant professor in the School of Humanities at the University of Florida, Hamilton College, and the author of "The Domain of All Mankind: How Outer Space Became U.S. Foreign Policy."