Yonaguni is a small island of cliffs, horses and rice terraces, and it is the westernmost place Japan reaches. Taiwan is 110 km away; on clear days you can see it from the hills. Japan is putting radar and Type 03 air-defence missiles on the island, part of a line of installations running down the archipelago toward China. DW's Mapped Out uses that one island to ask a larger question: why is a country whose constitution renounces war now on course to be the world's third-largest defence spender?

The answer the film gives is about China, Taiwan and a crumbling world order. The answer I keep coming back to is narrower and, I think, more portable: this is what it looks like when a country decides its security guarantee can no longer be trusted, and starts paying to take the capability back in-house. Japan has been running that experiment for eighty years. Europe started running it on AI in June.

What Japan outsourced

After 1945 the Allies demilitarised Japan under US command and wrote pacifism into the constitution. Article 9 renounces war and leaves only self-defence. Eight decades later the effects are still audible in the vocabulary: the armed forces are a self-defence force, roughly 250,000 personnel, no conscription. The missing capability was supplied by someone else — Japan hosts more US troops than any other country, and those bases are at once Japan's insurance policy and part of a US strategy to hold China inside the first island chain.

That arrangement worked as long as two things held: the guarantee was credible, and the neighbourhood was quiet. Sheila Smith of the Council on Foreign Relations — whose book on this is literally called Japan Rearmed — has argued for years that neither holds any more. Koichi Nakano, who writes on Japanese politics and nationalism, is blunter about which half broke first.

The repricing

On 7 November 2025 Prime Minister Sanae Takaichi told a Diet committee that a Chinese blockade of Taiwan could be a “survival-threatening situation” for Japan — the legal phrase that unlocks collective self-defence. Japan had spent decades not saying that out loud. Beijing's answer was economic: a suspension of Japanese seafood imports, a travel advisory telling Chinese citizens to stay away, flights cut. On 27 January 2026 Japan's last two pandas flew home to Sichuan, leaving the country without them for the first time in over fifty years.

Then the part the film mentions only in passing. On 8 February 2026 Takaichi gambled on a snap election and won 316 of 465 lower-house seats — the first time since the war that a single party has held two-thirds. That majority is not just a mandate for a defence budget. Two-thirds is the threshold to propose amending the constitution. Eight decades of pacifist identity became, in one evening, a thing that can be put to a vote.

The money moved on the same schedule. Japan's five-year buildup — doubling defence spending to 2% of GDP — was pulled forward under US pressure to March 2026, two years early; it landed just short, at about 1.9%. On an economy that size, that still makes Japan the third-largest defence spender in the world, after the US and China. Long-range missiles have been deployed, nuclear weapons are now discussed out loud, and in April roughly 1,400 Japanese ground troops joined the Balikatan exercises in the Philippines — the first Japanese combat units on Philippine soil since the war, firing a Type 88 anti-ship missile outside Japan for the first time.

And still, the cheque

Here is the part that complicates the story. The same government that decided Washington is unreliable also pledged $550 billion of investment in the United States, in exchange for a cap on Trump's tariffs. Takaichi has refused to reopen the deal — promises between governments shouldn't change with the prime minister, she says — and a year on, about 20% of the money is actually moving. Some of the defence increase is aimed at China. Some of it is aimed at keeping the White House happy.

So the sequence runs: decide the guarantor can't be relied on, then pay the guarantor more. It reads as contradiction and isn't. Rebuilding a capability you gave away takes decades, and you still need cover while you build. Nakano's verdict on where that leaves Japan right now is the bleakest line in the film.

Why this belongs in the Almanac

I keep an almanac of AI and the rules; its first issue is a dashboard of the gap between what AI can do and when anyone decides anything about it. There is no AI in this film — that is exactly why I filed it. The board's hardest open question is whether a bloc that doesn't build its models, chips or clouds can set its own AI rules, or whether dependency becomes a veto held abroad. June 2026 turned that from theory into news: the US switched Anthropic's Fable 5 and Mythos 5 off overnight for foreign nationals; France's intelligence service dropped Palantir, its prime minister warning against depending on partners “capable of turning off the access tap”; Germany followed, and Spain became the sixth EU government to freeze new contracts.

That's year one. Japan is year eighty, and it shows what the invoice looks like when it finally arrives: a constitutional fight, a doubled budget, decades of rebuilding, a hostile neighbour to manage during the rebuild — and the guarantor still holding enough leverage to extract $550 billion on the way out. Europe's version will be cheaper in blood and slower in nothing else. The reason the gap widens is not that anyone is slow to notice. It's that dependencies unwind far more slowly than the guarantees they rest on decay, and paying to stay is always the cheapest thing to do this quarter.

• 8 Feb 2026: Takaichi's LDP takes 316 of 465 seats — the first single-party two-thirds since the war, enough to propose amending Article 9.
• Defence spending was pulled forward to the 2%-of-GDP target by March 2026 and landed near 1.9% — still the world's third-largest budget.
• Yonaguni, 110 km from Taiwan, is getting Type 03 air defence; the deployment date has been given as both Feb 2026 and FY2030.
• April 2026: ~1,400 Japanese troops at Balikatan — first combat units on Philippine soil since 1945.
• $550bn pledged to the US for tariff relief (deal July 2025, tariffs capped at 15%); a year on, ~20% is underway.
• The transferable lesson: a dependency takes decades to unwind, and the first instinct is to keep paying the party you no longer trust.

• DW News — What's behind Japan's military buildup (Mapped Out)↗
• CNN — Takaichi secures a historic supermajority (8 Feb 2026)↗
• Bloomberg — Japan's defence budget lands just short, at 1.9% of GDP↗
• The Japan Times — a year on, 20% of the $550bn pledge is underway↗
• The Diplomat — Japan sends combat units to Balikatan for the first time↗