The American Institute in Taiwan (AIT) on July 28 posted on social media a picture of Taiwanese and US coast guard vessels sailing in formation, the first confirmation of the two countries’ combined patrols in waters near Taiwan.

The post showed the 4,000-tonne Chiayi-class vessel Taipei and 4,500-tonne Legend-class cutter USCGC Midgett sailing together in the Taiwan Strait, and said that Taiwan and the US coast guard were coordinating on shared maritime objectives, such as preserving maritime resources and interdicting illegal drug shipments.

“The US appreciates Taiwan’s partnership in maritime security and safety, and supports Taiwan’s meaningful contributions on global issues,” it said.

The two countries in 2021 signed a Memorandum of Understanding on Establishing the Coast Guard Working Group and have carried out several anti-smuggling and rescue exercises.

The AIT’s post came amid China’s escalating maritime “gray zone” coercions — such as harassing commercial ships, shadowing Taiwanese and international vessels, and conducting blockade rehearsals and “law enforcement” drills — which contravene international norms and have caused regional turmoil.

Other countries have condemned Beijing’s actions against its neighbors, but the AIT’s post aimed to deter China’s expanding presence in regional waters by showing the growing regional security cooperation between Taiwan and the US.

Hudson Institute China Center director Miles Yu, a China policy adviser to US President Donald Trump during his first term, said the AIT’s post was ‘the most important security development in East Asia this year.”

The joint patrol showed that the US does not accept China’s claim over Taiwan’s surrounding waters, and “affirms that Taiwan exercises lawful maritime jurisdiction in its own waters and those waters remain part of international maritime commons,” Yu said.

Although the US-China leaders’ summit in May and next month sparked concerns on Trump’s stance on the Taiwan issue, German Marshall Fund Indo-Pacific program managing director Bonnie Glaser said the post conveyed a message from Washington that “Taiwan is an important partner for regional security, and the US is committed to working alongside Taiwan to promote shared objectives.”

To other countries, it signals that they “could also benefit from working more closely with Taiwan,” Glaser added.

While the US’ national security strategy under Trump’s second term has emphasized a shift toward asking partners to share responsibility for their own defense and regional security, China’s maritime aggressions against Japan in the East China Sea, the Philippines in the South China Sea and Taiwan in the Taiwan Strait have given First Island Chain nations a common foe. Japan and the Philippines this year announced they would elevate bilateral relations to a “comprehensive strategic partnership,” which is obviously an alliance to counter shared security challenges from China.

Following Japanese Prime Minister Sanae Takaishi’s statement that a Chinese attack against Taiwan could constitute a “survival threatening situation” for Japan, the Philippines’ president and secretary of national defense have also said that Manila would be involved if Beijing were to attack Taiwan, as its geographic proximity makes neutrality impossible.

Tokyo in its latest Defense of Japan white paper portrayed China’s military growth and coercion as the “greatest strategic challenge“ to Japan, detailed Beijing’s military operations and incidents around Taiwan and highlighted the growing military gap across the Strait as a matter of great concern to the region and the international community.

The report also for the first time devoted a special chapter on the modernization and reform of the Japan Self-Defense Forces and firmly asserted that Tokyo would reinforce its alliance with Washington.

Japan would also deepen partnerships with like-minded countries in the Indo-Pacific region and the EU “to uphold a rules-based international order against unilateral, coercive attempts to change the status quo,” it said.

Japanese destroyers sailing through the Taiwan Strait this year and last year, and Japan’s white paper and defense reforms reflect China’s failure in escalating its pressure campaign against Tokyo, the aim of which is to deter it from getting involved in a Taiwan contingency.

The joint patrol signals that a wider and more “paramilitary” maritime alliance is forming along the First Island Chain, with Taiwan at the center and the strategic anchor of the chain. Taiwan must enhance cooperation and partnerships with more like-minded countries to ensure stability and prosperity in the region and the Indo-Pacific area.