A Taiwan Crisis Could Shake Japan's Economy Before War Begins
When we hear the phrase “a Taiwan contingency,” we tend to picture warships and fighter jets. But the first changes affecting Japan's economy may emerge somewhere other than a battlefield at sea.
Shipping operators. Cargo insurers. Factories ordering semiconductors. Trading companies procuring fuel. And financial markets pricing risk. If people's decisions begin to change before a war starts, logistics and prices can start moving as well.
In this edition of NIGHT FLIGHT, we take that question as our starting point and examine developments around Taiwan through the lens of an economic early-warning radar for Japan.
01 | Three Stages We Must Keep Separate
Stage 1: Military pressure and preparations. These include exercises, legal frameworks, and mobilization capabilities. They may indicate heightened tensions, but they do not tell us when a war might begin.
Stage 2: Precautionary moves by companies and markets. Examples include revised shipping schedules, changes to insurance terms, increased inventories, and diversified suppliers. These can occur without an actual clash.
Stage 3: Actual disruptions to supply and logistics. These include restricted shipping routes, delivery delays, higher procurement costs, and adjustments to factory production. At this stage, corporate earnings and household finances may also be affected.
02 | Watching Five Radars at Once
| Radar | What to monitor | How to interpret it carefully |
|---|---|---|
| Maritime shipping | Route changes, transit times, freight rates, and vessel movements | Distinguish geopolitical effects from seasonal patterns and normal supply-demand shifts |
| Marine insurance | War-risk premiums, underwriting terms, and covered waters | Check insurers and industry sources rather than relying on rumors |
| Semiconductors | Taiwanese manufacturers' operations and lead times, customer inventories, alternative sourcing | Separate geopolitical effects from shortages driven by AI demand |
| Oil and LNG | Shipping routes, freight rates, procurement costs, and inventories | Middle East developments and global supply-demand conditions also matter greatly |
| Currencies and Japanese stocks | Yen, U.S. dollar, Taiwan dollar; relative performance of heavy industry and semiconductor shares | Interest rates, earnings, and index-driven trading can also explain movements |
03 | Why Focus on Marine Insurance?
Whether a ship can operate depends on more than whether a sea lane is physically navigable. Operating risks, insurance premiums, crew safety, shippers' decisions, and conditions at ports all play a role.
If the risk associated with a particular area is judged to have risen, insurance terms and freight rates may change. Even before a single ship stops sailing, higher transport costs could alter business decisions.
However, we cannot simply conclude that higher insurance premiums mean a Taiwan crisis is imminent. Premiums are also affected by conflicts elsewhere, reinsurance markets, and shipping supply and demand. Comparisons across regions and against historical levels are essential.
04 | Taiwan's Semiconductors Are Connected to Japan's Factories
Taiwan is a major manufacturing center for advanced semiconductors. Japanese companies in automobiles, industrial machinery, electronics, and data-center-related industries are connected, directly or indirectly, to Taiwan's semiconductor supply chains.
To assess the potential impact, asking only whether factories in Taiwan will stop is not enough. We must also examine transportation, components, electricity, packaging, alternative manufacturing capacity, and inventory coverage.
Conversely, a fall in semiconductor stocks alone is not evidence of a supply disruption. Higher U.S. interest rates or profit-taking in AI-related stocks can also move share prices.
05 | With Oil, Ask Whether It Can Arrive—Not Just What It Costs
In an earlier NIGHT FLIGHT SPECIAL, we asked how to anticipate whether oil would reach Japan. The situation around Taiwan is an extension of that inquiry.
Even if the resources Japan needs exist somewhere in the world, that means little unless the required quantities can arrive at the right time and at a reasonable cost.
Crude oil futures prices are not the only indicators worth watching. Tanker routes, estimated arrival dates, freight rates, insurance, alternative suppliers, and stockpiles also matter. We will assess how much tensions around Taiwan affect each factor by accumulating verifiable evidence.
06 | Are Japanese Stocks an Alarm Bell—or Just Noise?
At Yorimichi Research Laboratory, we continuously monitor Mitsubishi Heavy Industries (7011), Kawasaki Heavy Industries (7012), and IHI (7013). We also follow semiconductor-related stocks.
One hypothesis is that heightened concern about Taiwan could channel money into defense-related stocks and out of semiconductor-related stocks. In practice, however, earnings, currencies, interest rates, and market supply and demand can all have a substantial impact on prices.
We therefore examine not only share prices but also trading volume, VWAP, relative strength, peer movements, and the timing of relevant news. A market move that precedes a headline does not justify retroactively attributing it to that single story. That is a basic rule of verification.
07 | Our Monitoring Procedure for Next Week
| Order | What to check | When to reconsider the hypothesis |
|---|---|---|
| 1 | Are there sustained changes in routes, freight rates, or insurance terms around Taiwan? | The change proves temporary, or the same movement occurs in unrelated regions |
| 2 | Do official statements by chipmakers or their customers indicate changes in lead times or sourcing? | Normal supply-demand conditions or product cycles provide a sufficient explanation |
| 3 | Have transport or procurement terms for oil and LNG bound for Japan changed? | Middle East developments or global supply-demand conditions turn out to be the main cause |
| 4 | Are capital flows between Japan's three heavy-industry stocks and semiconductor stocks consistent with the timing of relevant news? | Interest rates, exchange rates, or earnings explain the moves better |
08 | Our Hypothesis and Provisional Conclusion
Hypothesis: When tensions around Taiwan affect Japan's economy, changes in maritime transport, insurance, and procurement behavior may sometimes appear before any military clash.
What remains unknown: When such changes might occur, how large they might be, and which indicators would show them. At present, there is no basis here for predicting a specific date for war or a supply cutoff.
Next step: Rather than drawing conclusions from a single headline or stock price, place logistics, insurance, corporate disclosures, and market data on the same timeline.
If all we do is follow the news, each day may bring fresh anxiety. But when we decide what to observe and what evidence would make us revise a hypothesis, anxiety becomes a question we can test.
The waters around Taiwan, factories in Japan, ships carrying fuel, and the Tokyo market may seem far apart. In reality, they are linked along the same route.
This week, NIGHT FLIGHT turns its radar toward that route.