TCSS Security Commentaries #019
Rising temperatures in the Taiwan Strait have reached the shores of Japan in the latest defense white paper from Tokyo. While Tokyo continues to abide by the One-China Policy as does most of the international community, the report outlines growing interest and higher stakes for Japan in the matter of Taiwan’s security.
Richard Chen, Taiwan Center for Security Studies

The white paper, titled “Defense of Japan 2021”, was released by Japan’s defense ministry on July 13th. In it, the report emphasized making clear the commitment that Tokyo has towards the vision of a “Free and Open Indo-Pacific” (FOIP) with likeminded nations, partners and allies. With a special emphasis on the situation unfolding in the Taiwan Strait, in the same vein calling on Japanese defense officials to pay greater attention to the military trends of China and US.
The fact that Taiwan has been referred within these documents, notably the first time for Japan, is echoing the diction coming out of the liberal democracies and US allies in these past few months. For the most part hitherto, even under previous Prime Minister Shinzo Abe, cooperation in its official relationship with Taiwan have been majorly focused on economic and business ties, despite nods towards the sensitivity of the Taiwan issue as well as public support. However recently, prior to the white paper’s release, top Japanese officials have begun to make waves in voicing their concerns and at times outright support for Taiwan’s security, unsurprisingly drawing much ire from Beijing.
In June, at a Hudson Institute event on Japan’s Security Strategy, Japan’s deputy defense minister says Taiwan must be protected “as a democratic country”. Deputy PM Taro Aso, stated in Tokyo earlier this month that Japan would have to defend Taiwan with the United States if the island is invaded by mainland China, as such a major event would be a “survival-threatening situation” for Japan. Japan under its Constitution is only allowed to exercise its right of collective self-defense to come to the aid of an ally in the event of an attack that threatens Tokyo’s own security.
However, despite these policy statements that seem to raise the Tokyo-Taipei security relationship to new highs, even Prime Minister Suga clarified during a Diet meeting in Tokyo that Japan does not ““presuppose military involvement at all” with regards to any military contingencies surrounding the matter of Taiwan.
Nonetheless, the white paper outlines the US-China relationship specifically as a major component upon which Japan’s security is now intertwined with moving forward. This geopolitical foundation upon which a peaceful and stable Indo-Pacific is built upon, according to the report, behooves all parties and relevant stakeholders in Japan to pay greater attention to “stabilizing the situation surrounding Taiwan” (p.19). Details on how to stabilize current escalations further zero in on the ever-growing military imbalance between Taiwan and China. Seeking to actively pay closer attention to US arm sales to Taipei, as well as the island’s self-development in military equipment for a changing security environment, Japan will likely align and insert its own priorities alongside the US with regards to the Pentagon’s “integrated deterrence” concept in the months ahead.

On Wednesday, US Deputy Secretary of State Wendy Sherman said in a roundtable discussion during her weeklong Indo-Pacific tour, that the US is continuing its One-China Policy, “that said, we have deepened our unofficial relationship with Taiwan”. According to Nikkei Asia, Sherman further elaborated that the US has established a “stronger economic relationship [as well as] a stronger political and security relationship with Taiwan”.
Subsequently, Japan’s defense white paper comes at a time when the US and its allies are scaling up its engagements in the region, strengthening interoperability through a diverse set of regional partners. Be it with through the QUAD, or its military alliances—the ongoing Talisman Sabre 2021 (TS21) drills recently commenced with additional participation from a number of allies including Japan, South Korea, and the UK—, Japanese military planners have internalized the “sense of crisis” pacing in its immediate backyard.