As populist shocks upend the globe, Japan is a fascinating study in calm. Explaining why is a fashionable preoccupation among economists and pundits. Some credit socialist mores that soften capitalism's sharpest edges, others an entrenched political system impervious to insurgency. A cultural preference for harmony over disruption also factors into the equation. But even as Japan avoids a Brexit moment or a Donald Trump-like jolt, it's tripping over nationalism in unappreciated ways. The proof isn't angry protests, defaced cemeteries or social-media backlashes — it's the underperforming economy.

It says everything about Tokyo's plight that a 0.1 percent gain in inflation is reason to rejoice. Never mind that the first rise in consumer prices in 13 months in January was an imported-oil phenomenon — bad inflation, in other words — Prime Minister Shinzo Abe's policies, it's said, are finally working. Such optimism is belied by a 1.2 percent drop in household spending. That drum tight labor markets — 3 percent unemployment — aren't boosting wages or spending is as much a riddle to economists as the dearth of populist angst.

Abe's nationalism helps explain why. In a March 2 Wall Street Journal column, Greg Ip connected the dots between Brexit, Trump, Hugo Chavez and possible upheavals in France, Hungry and elsewhere to reduced trade and prosperity. It's complicated, of course. "Unfortunately," Ip hedges, "what's bad for democracy isn't automatically bad for growth — just look at China."