For every U.S. administration, the Taiwan question is critical to which direction its relationship with China is headed: Does it adhere to the one-China policy and oppose Taiwan independence?

This question has been fundamental to bilateral ties since the two countries established diplomatic relations in 1979, with a status quo maintained through the best and the worst.

Last week, in its first public statement clarifying the U.S. stance on the island region, the Biden administration drew the line once again, saying that the U.S. does not support Taiwan independence. Previously, Secretary of State Antony Blinken and State Department spokesman Ned Price also said that there was no change in the one-China policy.

Signaling a continuation of Washington's decades-old official position, the White House's coordinator for the Indo-Pacific Kurt Campbell said on July 6 that the U.S. supported a "strong unofficial relationship" with Taiwan, but not independence, despite recent actions from the country suggesting the contrary.

The statement came as Taiwan leader Tsai Ing-wen's Democratic Progressive Party (DPP) fawns over the U.S. amid heightened cross-strait tensions. As the region faces a worsened COVID-19 outbreak and a vaccine shortage, the DPP leadership has turned to the U.S. and Japan over the mainland's more substantial offer, making clear where its alliance lies.

But in another sign of its choice to tread carefully on the issue, the White House COVID-19 Response Team deleted a Twitter post on July 7 showing a Taiwan flag among those of others receiving U.S. vaccine donations. After the post was retweeted by Tsai, who thanked the U.S. for its "generosity," its subsequent removal prompted DPP authorities to ask the U.S. not to cause "unnecessary speculation or misunderstanding."

The White House press secretary later called the original post "an honest mistake" while reiterating the U.S. commitment to the one-China policy.

However, Tsai's leadership has grown closer with the U.S. through nonofficial channels, further emboldening the DPP to test Beijing's limits. In April, the Biden administration issued new guidelines regarding contact between the U.S. government and Taiwan officials.

Meanwhile, military provocations from the U.S. side, including the landing of a transport aircraft in the Taiwan region on Thursday, have escalated markedly in recent months, drawing stern warnings from Beijing.

Two-sided ambiguity

The legacy of the Trump administration's policy on Taiwan has been mostly passed down to Biden's White House. This has given Tsai, the first Taiwan leader to overlap with two U.S. governments, renewed hope and confidence that her pro-independence party has U.S. backing, Professor Wang Bin from the Center for Taiwan and East Asian Studies at Central China Normal University told CGTN.

There has been speculation that the ambiguous U.S. strategy over Taiwan might be coming to an end. Raymond Greene, a senior U.S. diplomat in the region, said last month that the U.S. "no longer sees Taiwan as a problem in its relations with China, but as an opportunity to promote a free and open Indo-Pacific."

"This view of Taiwan as being part of a U.S.-led Asia-Pacific order has not changed," Wang said. However, after the previous administration's actions, it is no longer possible for Biden's America to return to the "strategic ambiguity" of the Obama era, he noted.

Under the Trump administration, the U.S. came extremely close to crossing the line on Taiwan with the lifting of restrictions on official visits. On one occasion, former Secretary of State Mike Pompeo even publicly spoke of the region as not being part of China.

"This administration's ambiguous strategy will be different and strongly two-sided," Wang said. "Ties between the U.S. and Taiwan have deepened, but there remains a safe distance from the 'red line'."

The U.S. wants to send out a message that it still has the upper hand in Asia-Pacific affairs, but it is not in the country's interests to risk conflict with China over the island, Wang said. Due to China's growing strength, the difficulty and the costs for Washington to maintain the status quo and keep leveraging the Taiwan issue have both increased, he added.

An anti-China alliance?

The return of America as a respected world leader with strong geopolitical alliances has been the hallmark of the Biden administration's foreign policy vision.

Located on the first Pacific island chain, the U.S. considers Taiwan the frontline in its Indo-Pacific Strategy, the 2019 defense report aimed at containing China. Taiwan was mentioned in recent statements with U.S. allies, including G7 members, Japan and South Korea, all in the context of countering China.

"Taiwan is ranking higher among issues that are used to undermine China. But the language now has changed from countering China to defending Taiwan and maintaining regional stability," noted Cai Liang, a senior researcher at the Center for Asia-Pacific Studies of Shanghai Institutes for International Studies.

The U.S. tries to shift the blame for cross-strait tensions by framing Beijing as the aggressor, Cai said. "In that sense, Biden's America is worse for China."

Taiwan's DPP, on the other hand, sees an opportunity to stoke up anti-mainland sentiments among its supporters. Fueling fears about unification with the mainland is the party's way to win the region's leadership election and hold on to power, Cai said. 

"The DPP's primary concern is elections, rather than Taiwan's long-term stability or cross-strait relations," Cai told CGTN. 

"It understands the mainland's bottom line and also its usefulness to the U.S., therefore is not willing to upset the status quo by declaring independence, though its actions seek just that," he said. "And that is a situation Beijing must prepare to deal with for a long time to come."