Beijing has warmly welcomed Sao Tome and Principe's decision to sever "diplomatic ties" with Taiwan, praising the West Africa country for returning to the correct path of recognizing one China.

Since the move means there are now only 21 countries and governments still maintaining official ties with the island, and it signals another blow for the pro-independence maneuverings of the Democratic Progressive Party on the island, it is not surprising that the DPP has bemoaned the move.

Unlike her predecessor, Kuomintang leader Ma Ying-jeou, who recognized the 1992 Consensus on the principle of one China, DPP leader Tsai Ing-wen has tried to avoid acknowledging the agreement there is only one China. This obscurantism has strained cross-Straits ties and limited the room for any meaningful exchanges between the two sides.

And while claiming to support the status quo that existed under her predecessor, the phone call she and US president-elect Donald Trump engineered as a petty political gambit to challenge the principle of one China, has shown there can be no doubting this is not the case.

It is unwise for Tsai to try and cling to the shirttail of the president-in-waiting's pre-office attempts to gain an upper hand in his country's dealings with Beijing, since Trump said he fully understands the situation.

The unsolicited comment by a French Foreign Ministry spokesperson on Tuesday that France is committed to the principle of the unity of China and its stance is "constant and unambiguous" shows countries realize one China is not something that can be used as a bargaining chip to gain benefits from Beijing.

Indeed, the principle of one China was acknowledged by the United Nations in 1971 in Resolution 2758, which recognized the People's Republic of China as "the only legitimate representative of China". That has now become the prevailing consensus worldwide.

Over the years, Beijing has demonstrated ample goodwill to Taipei, in the form of trade and economic deals, and cross-Straits exchanges. It has never tried to block the island's access to any international organization whose membership requires no statehood. After all, people in Taiwan and the mainland are "brothers connected by flesh even if our bones are broken".

But all this has been made possible by the island upholding the principle there is only one China.

Those remaining 21 countries and governments still maintaining official ties with the island should follow the advice French Foreign Minister Jean Marc Ayrault offered Trump, and show more "responsibility" to the true and accepted principle of one China.