Japan’s defence modernisation is a critical component of regional stability, the country’s defence minister has told the BBC, as the United Kingdom reaffirmed its commitment to Tokyo as a cornerstone of its Indo-Pacific tilt. In an interview broadcast on Wednesday, Japanese Defence Minister Minoru Kihara described his government’s ambitious five-year military expansion as essential to deterrence in a increasingly contested neighbourhood.
The remarks come as Britain deploys its HMS Prince of Wales carrier strike group to Japanese waters for joint exercises in 2025, the latest milestone in a defence partnership that has deepened since the 2023 Hiroshima Accord. UK Defence Secretary John Healey, speaking after talks with Kihara in London, described Japan as “one of our most important partners in the Indo-Pacific” and praised its “significant and necessary” investment in new capabilities.
Tokyo’s defence build-up is the largest since the Second World War. It includes the acquisition of long-range cruise missiles, the establishment of a joint operations command, and a doubling of the defence budget to 2% of GDP by 2027. The programme is driven by perceived threats from China’s military assertiveness, North Korea’s missile tests, and Russia’s war in Ukraine.
“We face the most severe security environment since the end of the war,” Kihara said. “Our defence build-up is not about aggression. It is about ensuring we have the capability to protect our territory and contribute to regional peace.” He stressed that Japan’s new strike capabilities would be used only for self-defence.
British officials emphasised interoperability as a key objective. The Royal Navy’s deployment will involve joint anti-submarine warfare exercises, air defence drills, and amphibious operations with Japan’s Maritime Self-Defence Force. The two countries are also collaborating on the Global Combat Air Programme, a next-generation fighter jet project with Italy.
Analysts say the deepening UK-Japan defence relationship reflects a broader shift in British foreign policy. Since leaving the European Union, successive governments have prioritised the Indo-Pacific, alongside NATO, as a strategic theatre. The 2021 Integrated Review identified Japan as the UK’s “most significant security partner in Asia”.
“Japan is no longer a quiet ally,” said Dr. Yuki Tatsumi, director of the East Asia program at the Stimson Centre. “It is becoming a proactive military power, and the UK is one of the few European nations that can match its ambition in the region.”
But the build-up is not without controversy. China has accused Japan of “breaking its pacifist tradition” and warned of an arms race. Domestic critics, including some opposition lawmakers, question whether the equipment can be funded in a rapidly ageing society with high public debt.
Kihara rejected such concerns. “We are making responsible choices,” he said. “Our democracy and our alliance with the United States remain the foundation. But we must do more for ourselves.”
