Japan Bond Rout Pressures Prime Minister Takaichi's Fiscal Strategy, Analysts Warn

Japan is running low on options to contain a bond rout that could push debt-financing costs above government estimates, leaving Prime Minister Sanae Takaichi's ambitious spending agenda hostage to forces beyond her control, analysts say.

The benchmark 10-year Japanese government bond (JGB) yield hit a three-decade high of 2.945% on Tuesday before retreating to around 2.89% on Wednesday, according to Reuters. The yield is on the brink of surpassing 3% for the first time since the mid-1990s, as investors grow increasingly nervous about the country's towering debt pile and inflation risks stemming from the Middle East war.

The surge in yields is emerging as a critical test for Takaichi's economic strategy. Her case for increased spending rests on the assumption that economic growth will outpace long-term borrowing costs, allowing Japan to sustain its enormous debt burden without jeopardising fiscal stability, the reports noted. That premise would come under doubt if the 10-year yield exceeds 3% with inflation running at 2% and real growth hovering around 1% at best.

In estimates released in July, the Japanese government expects real GDP growth of 0.9% in the current fiscal year ending March 2027, followed by 1.1% the next year, per the sources.

A sustained move above 3% — the very level the government used as its budget assumption — would send debt-financing costs surging past the 31 trillion yen ($195 billion) currently set aside for fiscal 2025, while simultaneously undercutting Takaichi's signature push to pour investment into growth sectors, the sources said. Under the finance ministry's baseline estimate assuming the 10-year yield will climb to 3.6% in fiscal 2029, debt-servicing costs would rise to 41 trillion yen that year.

Making matters tougher, the government has ruled out spending caps on requests for strategic growth sectors in next year's budget, a move that could force more debt issuance on top of revenue already lost to a planned food levy cut, the reports showed.

"Japan hasn't experienced such sticky price pressures since the previous oil shock," Mari Iwashita, executive rates strategist at Nomura Securities, was quoted as saying. "The challenge of anchoring inflation at the BOJ's 2% target is becoming bigger."

Although government subsidies have kept core inflation below 2%, the Bank of Japan has warned of the risk of an inflation overshoot that could warrant an early rate hike, according to the sources. The prospect of sooner and faster rate hikes has reduced concerns that the BOJ is falling behind the inflation curve, but it has also fueled a repricing across bond markets. Investors now see a realistic path toward rates reaching 2%, well above earlier expectations for a peak near 1.5%, analysts said.

**Limited Tools in the Toolkit**

As bond jitters persist, markets are increasingly focused on whether policymakers have credible options to contain the selloff. Analysts say the tools available — sporadic cuts to bond issuance or emergency central bank buying — amount to little more than temporary patches for a bond market being squeezed by stubborn inflation and an increasingly loose fiscal stance.

The finance ministry could make ad hoc cuts to bond issuance or heed concerns on over-supply in a regular meeting with investors slated for next month, analysts said. "An adjustment to bond issuance at an irregular timing could help curb yield rises," as well as any sign the ministry could contemplate cuts to 10-year bond issuance, Ataru Okumura, chief rates strategist at SMBC Nikko Securities, was cited as saying.

Another option is for the BOJ to ramp up bond-buying in emergency market operations, a tool it has kept in reserve even while tapering purchases, meant for sharp, disorderly yield spikes that threaten financial stability. While the BOJ won't rule out the step entirely, it likely sees little need to step in now with recent yield rises driven by fundamentals, said a source familiar with the central bank's thinking.

Many analysts argue yields will remain under upward pressure unless the government rethinks its reliance on subsidies and tax cuts to ease cost-of-living pain, an expansionary approach that only fuels demand and inflation.

"The BOJ can't anchor inflation expectations if the government is ramping up fiscal spending and adding to price pressures from the Middle East war," Naomi Muguruma, chief bond strategist at Mitsubishi UFJ Morgan Stanley Securities, was quoted as saying. "Inflation has now become the key risk for anyone trading JGBs," she said. "At the heart of the problem are market doubts over the government's resolve to combat inflation."