• A US Navy P-8A Poseidon anti-submarine aircraft transited the Taiwan Strait on Tuesday.
• China had fighter jets tail the plane as it flew through
• Just days earlier, German warships transited the Taiwan Strait, angering China.

A US spy plane flew above the Taiwan Strait in international airspace, prompting a response from China.

The event comes just days after German warships made a notable transit through the tense waters in defiance of China.

China’s military reported that the American P-8A Poseidon maritime patrol aircraft’s activity over the Taiwan Strait on Tuesday. A spokesperson for China’s Eastern Theater Command said that fighter jets were dispatched to tail the aircraft.

The US Navy’s 7th Fleet confirmed the operation, saying that the anti-submarine warfare aircraft operated “within the Taiwan Strait in accordance with international law” and upheld “the navigational rights and freedoms of all nations.”

“The aircraft’s transit of the Taiwan Strait demonstrates the United States’ commitment to a free and open Indo-Pacific. The United States military flies, sails and operates anywhere international law allows,” it added.

China previously documented P-8A activity in the Taiwan Strait in April of this year, as well as December and October of last year. In each case, the Eastern Theater Command said it sent out warplanes to follow “the trespassing US aircraft according to law and regulations.”

China’s military said that its forces “remain on constant high alert and resolutely safeguard national sovereignty and security as well as regional peace and stability.”

The event comes on the heels of German Navy vessels transiting the Taiwan Strait last week for the first time in over 20 years. They chose that route because it was the shortest to the Philippines, and the Taiwan Strait is international waters.

The transit drew complaints and criticisms from China, with a Chinese Foreign Ministry spokesperson saying ” we firmly oppose any act of provocation under the pretext of freedom of navigation that harms China’s sovereignty and security.”

The Taiwan Strait is a trade route and international waterway. While the US and its allies have maintained that the route is open for freedom of navigation, and most countries acknowledge the right to “innocent passage” without notice, China views regulation of the strait differently and believes countries should navigate it in accordance with both Chinese and international laws.

The US P-8A Poseidon that recently passed through the area is a highly advanced maritime patrol and anti-submarine warfare aircraft widely considered to be one of the most sophisticated maritime patrol planes in operation.

The plane first entered service in 2013 and succeeded the older P-3 Orion. P-8As feature various technical and reconnaissance capabilities for detecting, tracking, and engaging submarines and vessels, as well as conducting surveillance.

The US Navy regularly flies these planes in international airspace. Its allies, too, have trained on the aircraft and flown it in various exercises and missions. Back in July, a Royal Australian Air Force P-8A, for instance, tracked a US Navy nuclear submarine off Hawaii in a joint exercise.