India, June 24 -- A Russian construction firm trains Indian recruits on-site to fit glass and aluminum because it cannot find enough workers at home. A Japanese care-home operator flies six Indian nurses to Osaka for nine months of language instruction before letting them near a patient. An Israeli builder, stripped of the Palestinian workforce he relied on for decades, tells officials he needs "close to 100,000" Indian workers to restart construction. These are not isolated anecdotes. They are data points in one of the most consequential and under-appreciated labour-market shifts of the decade.

The structural story is demographic, and it is not subtle. Rich countries are ageing faster than their training systems can replace blue-collar ...