The City of London has long viewed Japanese fiscal discipline with a mix of admiration and concern. Today, the news that British-backed minister Shinjiro Koizumi has declared Japan’s defence build-up ‘critical for peace’ sends a clear signal to markets: the era of underfunded security is over. But at what price? Gilt yields in Tokyo are already twitching, and investors are right to ask whether this surge is a prudent investment in stability or a reckless drain on the national purse.
Koizumi, a rising star in the Liberal Democratic Party, has been vocal about the need for a ‘fundamental rethink’ of Japan’s defence posture. With the government’s pledge to double defence spending to 2% of GDP by 2027, the numbers are stark. That is roughly ¥11 trillion a year, or £60 billion in real money. For context, that is more than the entire UK defence budget. And where will this money come from? Tax hikes, bond issuance, or the ever-dreaded ‘efficiency savings’ that rarely materialise.
The bond market is already pricing in the risk. Japan’s 10-year government bond yield, long suppressed by the Bank of Japan’s yield curve control, has crept up to 0.8%. A small move by historical standards, but a tremor that could become a quake if investors sense fiscal incontinence. The Bank of Japan is caught in a trap: normalise policy and risk a capital flight from Japanese bonds, or keep rates near zero and watch inflation erode the value of savers’ yen. The defence surge adds fuel to that fire.
British support for this move is telling. Whitehall, ever the pragmatist, sees a stronger Japan as a counterbalance to Chinese assertiveness in the Indo-Pacific. But UK taxpayers should take note: the Ministry of Defence’s own budget is already stretched thin. If Japan’s spending rise is ‘critical for peace’, then Britain’s own commitment to Nato’s 2% target looks increasingly like a floor, not a ceiling. Expect grumbling in the Treasury about defence inflation, a term that should worry every fiscal conservative.
Markets hate uncertainty, and Japan’s defence pivot introduces a new variable. Defence contractors like Mitsubishi Heavy Industries and Kawasaki Heavy Industries will surely benefit, but the broader equity market faces headwinds. The Nikkei 225 has enjoyed a remarkable run, up 20% this year, but valuations are stretched. A sharp rise in bond yields could trigger a rotation out of growth stocks and into value, a painful adjustment for portfolio managers who have grown complacent on cheap money.
Currency markets, too, are on alert. The yen, already weak against the dollar, could come under further pressure if the Bank of Japan is forced to taper its bond buying. A weaker yen boosts exporters but hurts consumers. And with inflation already above the BoJ’s 2% target, the central bank is running out of excuses for ultra-loose policy. The defence surge may be the catalyst that forces Governor Ueda’s hand, with all the volatility that implies.
Let me be clear: I am not opposed to defence spending. A credible deterrent is a public good, and Japan’s security environment has undeniably deteriorated. But fiscal responsibility demands that every yen spent on tanks and missiles is a yen not spent on healthcare, education, or debt reduction. Japan’s debt-to-GDP ratio is already 260%, the highest in the developed world. Adding tens of trillions in defence spending without a credible repayment plan is a gamble that could spook international investors.
Koizumi’s rhetoric is well-intentioned, but markets will judge by actions. If the government can deliver this spending through growth and reforms, without resorting to money printing, then the ‘critical for peace’ label may hold. If not, the fallout will be felt from Tokyo to London. The Bottom Line is this: Japan’s defence surge is a necessary evolution in a dangerous world, but it comes with a price tag that must be paid in hard cash, not vague promises. Investors, keep your eyes on those gilt yields.
