Apart from harming the health of American service personnel and posing a danger to aircraft safety, the use of lasers against U.S. military planes indicates two other major risks: It might trigger an inadvertent conflict between the U.S. and China, and could be part of a larger Chinese strategy of building maritime bases worldwide that could be used to undermine U.S. security interests.

Djibouti is strategically located, controlling access to vital international waterways joining the Red Sea and the Indian Ocean. Since the 9/11 terror attacks, it has hosted Camp Lemonnier, the only permanent U.S. military base in Africa and a critical hub also supporting American operations across the Middle East, Europe, and the Indian Ocean.

The Chinese government has denied any responsibility for the incidents, but there are strong grounds for skepticism. The U.S. military notice issued to warn pilots of the hazard refers to a location only 750 meters offshore from the Chinese base—which itself is only a few miles from Camp Lemonnier. Chinese military doctrine includes the use of lasers to blind adversaries: In 2015, the People’s Daily, the official mouthpiece of the People’s Liberation Army, reported that the PLA had been updating its “blinding laser weapons.” And Beijing has a history of dissembling about its military moves: It recently installed sophisticated anti-ship and anti-aircraft missiles in the Spratly archipelago, in further breach of President Xi Jinping’s public promise in 2015 not to militarize the South China Sea.

The first major risk of China’s use of laser weapons is that it could feed rising tensions between the U.S. and China and, in the worst case, lead to miscalculation and even inadvertent conflict. In 2001, a reckless Chinese fighter pilot collided with a U.S. EP-3 surveillance plane conducting a routine patrol, forcing the U.S. aircraft to make an emergency landing in China. Diplomacy resolved the crisis, but only after a tense standoff.

There are no guarantees a future incident will end peacefully. Washington and Beijing are already at loggerheads over trade and intellectual property theft, and the Trump administration’s 2018 National Defense Strategy broke new ground by formally labeling China a “strategic competitor.” The American and Chinese militaries are yet to negotiate the robust “rules of the road” that minimized the risk of inadvertent clashes between U.S. and Soviet forces even at the height of the Cold War. And the PLA has become increasingly assertive since the EP‑3 incident, with its ships and aircraft engaging in frequent unsafe encounters with U.S. and Japanese vessels and planes.

The second, longer-term danger is that China’s activities in Djibouti form part of a much broader—and troubling—pattern. The commander of the U.S. African Command testified before the Senate Armed Services Committee in March that the U.S. is closely monitoring Chinese “encroachment” on the American military presence at Camp Lemonnier. China has been building a chain of “dual-use” maritime facilities throughout the Indo-Pacific—often in strategic locations and close to U.S. bases. In peacetime these can be used to support the PLA’s increasing projection of military power, build influence with governments in the neighborhood, monitor American forces, and obstruct U.S. military access in a crisis short of actual conflict. But at any time of Beijing’s choosing, these facilities could rapidly be dedicated to military use.

The U.S. and its allies need to push back calmly but firmly against activities that jeopardize not only the safety of their personnel, but peace and stability in the Indo-Pacific—and America’s longer-term strategic position.

Andrew Shearer is a senior advisor on Asia-Pacific security at the Center for Strategic and International Studies. He was the national security advisor to prime ministers John Howard and Tony Abbott of Australia.