The visit to Taiwan by Japanese senior vice-minister of internal affairs and communications on Saturday was provocative and breaches the commitment made by Japan to interact with Taiwan only at nongovernmental and local levels.

It will definitely worsen relations between Beijing and Tokyo, which are already tense because of the Shinzo Abe administration's refusal to face up squarely to history and its previous provocative actions.

The one-day trip has set a bad precedent for bilateral ties. The fact that Jiro Akama became the highest-ranking Japanese government official to visit the island in an official capacity since 1972, when Beijing and Tokyo normalized their diplomatic relations, contradicted his claim that Japan's "relations with Taiwan are unchanged" despite the visit.

In fact, the visit represents a big step backward, as it goes against the spirit of the four political documents signed by China and Japan, and infringes on the one-China policy that is the foundation for relations.

Akama's visit will further freeze the already icy China-Japan relations, for which Tokyo, bent on participating in a US-led alliance to contain China, is fully to blame, as it has adopted a confrontational policy toward China.

Japan has already played an ugly role in the South China Sea disputes, even though it has no territorial claim in the region, by trying to drive a wedge between regional countries and China. On Monday, it delivered two military surveillance aircraft to help the Philippines patrol the South China Sea despite Manila's improving relations with Beijing.

This meddling, in addition to its announced plan to send its largest warship to the South China Sea, in its largest show of military power since the end of World War II, had already revealed its intention is to stir up trouble in the region.

But Japan must be careful in playing the Taiwan card. Since earlier this year, Japan has repeatedly taken provocative actions with regard to Taiwan, while verbally promising to honor its commitment to the one-China policy.

As the Taiwan question concerns China's core national interests, by uplifting the Japan-Taiwan relations to an unprecedentedly high level, Tokyo risks crossing Beijing's bottom line on the issue and it will have to bear any consequences that may arise from its duplicitous behavior. It should be aware that the one-China policy brooks no challenge.