The U.S. Navy has sailed ships through the Taiwan Strait throughout the last decade but normally kept those operations quiet — perhaps out of concern it would provoke China, who considers Taiwan its territory and the Taiwan Strait its territorial waters.

But in June, that changed. For the first time since 2007, both the U.S. Navy and Taiwan’s Ministry of Defense publicly confirmed that U.S. Navy ships sailed through the Taiwan Strait, on June 7 and 8.

According to a Taiwanese official, that “was the first time that both US Navy and Taiwan’s Ministry of Defense publicly confirmed such voyage since 2007.”

A U.S. Navy official confirmed that the U.S. Navy had gone “on the record” to confirm the June transit, and that it was the first time that had happened in recent memory. The official said previously there had been a “stranglehold” on discussing such operations that stemmed from the previous administration.

Accordingly, he and another U.S. Navy official declined to publicly confirm previous transits, including one last year in July 2017 that was reported by some U.S. and Taiwanese news outlets. The U.S. Navy allegedly made at least two transits through the Strait last year, but U.S. Navy and Taiwanese officials would not confirm that.

Commanders will typically determine in advance whether acknowledgment of an military operation will be “active” or “passive,” meaning the military could actively promote it with a press release or passively confirm when reporters ask. Sometimes officials will not confirm it at all, only saying such operations are “routine.”

The public confirmation of the recent transit coincides with the Trump administration’s desire to openly challenge China economically and militarily, including over Taiwan.

China considers Taiwan its “most important and sensitive” issue with Washington. Beijing asserts that Taiwan is a breakaway province of China instead of a separate country. The U.S. acknowledges China’s position but continues to provide Taiwan with defense equipment and treats it as a separate country.

Trump angered China early on by accepting a congratulatory call from Taiwan’s President Tsai Ing-wen on his election, the first time a U.S. president has spoken to a Taiwanese president in nearly 40 years. He also approved a $1.42 billion arms sale that Taiwan had proposed the previous year.

The White House issued a strong rebuke in May when China demanded that 44 international airlines change their websites to describe Taiwan as part of China, calling it “Orwellian nonsense.” The response drew praise from senior Taiwanese officials, who said they have never heard the U.S. use that kind of language before.

Trump has also appointed a number of Taiwan supporters to the administration, including National Security Adviser John Bolton, Assistant Secretary of Defense Randall Schriver, National Security Council Senior Director Matt Pottinger, and Deputy Assistant Secretary of State Alex Wong.

The White House also cast China as a “strategic competitor” and mentioned Taiwan in its National Security Strategy.

The Trump administration, early on in its tenure, launched an investigation into Chinese intellectual property theft, and more recently, has imposed 25 percent tariffs on $34 billion worth of Chinese imports. Washington has threatened more tariffs, and this week, the U.S. Department of Commerce slapped restrictions on dozens of Chinese companies, including developers of military technologies.

Last July, Breitbart News exclusively reported that Defense Secretary Jim Mattis had signed off on a plan to regularly challenge China’s excessive maritime claims in the South China Sea by sailing U.S. ships through the body of water. The Obama administration had put a stop on those transits between 2012 to 2015, out of concern for upsetting China.

This year, the Pentagon disinvited China from Rim of the Pacific (RIMPAC), the world’s largest biennial maritime military exercise hosted by the U.S. Navy after evidence showed that China had placed weapons systems on land features in the South China Sea, despite promising the U.S. it would not do so.

The transit of USS Mustin and USS Benfold through the Taiwan Strait in June, which angered China, may just be the latest sign of support for Taiwan and its willingness to challenge China.

Experts say there is not a lot of difference between the Trump administration’s Taiwan policy from the Obama administration’s, but they acknowledge the Trump administration has been more vocal in its support for Taiwan and that Taiwan is happy about it.

Bonnie S. Glaser, director of the China Power Project at the Center for Strategic and International Studies, said:

You can see a mention, for example, in the National Security Strategy of Taiwan, which might be for the first time. Some officials occasionally making statements that are supportive of Taiwan. Definitely the criticism of China for pressuring U.S. and other airlines to use China’s nomenclature of “Taiwan, China” — that was probably a high-water mark of U.S. support for Taiwan and criticism of China.

Some Taiwanese officials do worry that the U.S. could at any time reduce its support of Taiwan under pressure from China or use it as a bargaining chip with China. There are no signs that is happening but that worry makes every U.S. gesture on Taiwan fraught with significance.

For example, there was some disappointment in Taiwan that the U.S. did not send a senior-level White House official for the opening ceremony of its unofficial embassy in Taiwan on June 12. Taiwanese officials said they understood because it coincided with the Singapore Summit on June 12 and that they appreciated the administration sending Marie Royce, a senior State Department official and the wife of Rep. Ed Royce (R-CA), chairman of the House Foreign Affairs Committee.

And although the president signed the Taiwan Travel Act, which encourages the U.S. to send more officials to Taiwan, it is not clear yet whether that has been made use of. Congress has also authorized the U.S. Navy to make port calls in Taiwan, but it does not seem to have happened yet. China has warned the U.S. against doing so.

Congress, in recently passed legislation, calls on the U.S. to strengthen the defense relationship with Taiwan and to allow the U.S. and Taiwanese militaries to participate in each other’s military exercises, such as RIMPAC. However, Schriver, assistant secretary of Defense for Asian and Pacific Security Affairs, said last month at the Heritage Foundation that the administration was not considering allowing Taiwan to join RIMPAC.

The administration is also reportedly considering sending a U.S. Navy aircraft carrier through the Taiwan Strait — something it has not done since 2007. Schriver demurred when Breitbart News asked if that was under consideration, citing Pentagon policy of not discussing future operations, but said it is “certainly” within the U.S.’s right to do so.

Glaser said she would support doing so. “I would be in favor of sending an aircraft carrier through the Strait. China sends its aircraft carrier through the Strait, I think there’s nothing wrong with us doing that, you have to ask why we haven’t done it for 11 years,” she said.

Patrick Cronin, senior adviser and senior director of the Asia-Pacific Security Program at the Center for a New American Security, said although the Trump administration is moving forward with security, economic, and diplomatic support for Taiwan, “there is always more that can be done.”

He said first, the U.S. should periodically make “crystal clear” that Taiwan will not be a bargaining chip to achieve a grand deal — or even less, a better trade balance — with China.

Secondly, Cronin said the administration could do more to wean Taiwan from over-dependence on China, by supporting Taiwan’s indigenous innovation development and Southbound Policy to strengthen economic ties with its southern neighbors.

Thirdly, Washington can accelerate Taiwan’s plan to field an effective deterrent capability, to raise the costs in case China ever attempts to use military force against democratic Taiwan.

“But perhaps above all else, the United States should work with Japan and other allies and partners to ensure that the next generation of Taiwan movers and shakers appreciate the value of freedom,” Cronin said.

Glaser cautioned that any show of support would have to take into consideration China’s likely reaction.

“You also have to weigh that against what the reaction from China would be — because China will not punish the U.S., it will punish Taiwan,” she said.

“But we should try to come up with things we can do for Taiwan that will benefit Taiwan’s security in a meaningful way.”

This story has been updated.