Despite the stern warnings of multiple parties, there has been growing speculation that United States House of Representatives Speaker Nancy Pelosi might visit Taiwan during her Asian tour that began with a stop in Singapore on Monday.

If she makes the visit, she will be doing so despite US President Joe Biden reassuring the Chinese leader in their talks on Thursday that the US policy on Taiwan has not changed, and the US strongly opposes unilateral efforts to change the status quo or undermine peace and stability across the Taiwan Straits. And despite the Pentagon advising her it would not be a good idea.

The hoopla surrounding the possibility of her visiting the island and the glee of the anti-China politicians in Washington all point to the worrying fact that the troublemaker is being encouraged to make trouble beyond her remedy.

Her visit would constitute a grave challenge to China's sovereignty and territorial integrity. It would seriously violate the one-China principle the US committed to in the three communiques that are the foundation for diplomatic relations between the two countries, and thus belie Biden's reassurances.

The whole world knows which side is eating its own words, which side is stirring up trouble, and which side is taking unilateral actions to change the status quo of the Straits.

China has full legitimacy in international law to take all necessary means to safeguard its sovereignty and territorial integrity. The US' flexing its military muscles — no matter how many aircraft carrier strike groups it has sent to the region — will only consolidate China's resolve to accelerate reunification.

Should Pelosi visit Taiwan, it will be a watershed event in cross-Straits relations as well as Sino-US relations. On the one hand, it would take no more evidence to prove that the secessionist-minded Tsai Ing-wen administration on the island is incurably deluded.

On the other, the Biden administration would lose Beijing's trust by challenging the latter's redline again. The separation of powers in the US by no means makes Pelosi's Taiwan trip excusable.

If she does visit the island, it will deal a heavy blow to the already precarious Sino-US ties and add even more uncertainties to the already volatile global situation.

No force can stop China from achieving national reunification between Taiwan and the Chinese mainland. National reunification has never been a matter of yes or no, but a choice of path and time. If Washington tries, through such a provocative move as Pelosi's visit to the island, to test Beijing's tolerance of how far it can push the redline, it will soon know how badly the move has backfired.