That reality is spreading. Once-sizzling housing markets in Eastern Europe and the Baltic states are cooling rapidly, as nervous Western Europeans stop buying investment properties in Warsaw, Tallinn, Estonia and other real estate Klondikes.

Further east, in India and southern China, prices are no longer surging. With stock markets down sharply after reaching heady levels, people do not have as much cash to buy property. Sales of apartments in Hong Kong, a normally hyperactive market, have slowed recently, with prices for mass-market flats starting to drop.

In New Delhi and other parts of northern India, prices have fallen 20 percent over the last year. Sanjay Dutt, an executive director in the Mumbai office of Cushman & Wakefield, the real estate firm, describes it as an erosion of confidence.

Much of the retrenchment seems to be following the basic law of gravity: what goes up must come down. With low interest rates helping to inflate housing bubbles in many countries, economists said the confluence of falling prices was predictable, if unsettling.

This is not the first housing downturn to cross borders, but its reverberations have been amplified by the integration of financial markets. When faulty American mortgages end up on the books of European banks, the problems of the United States aggravate the world’s problems.

Consider Britain, which had one of Europe’s most robust housing markets, with less of an oversupply than in Ireland or Spain. Then last summer came the subprime crisis across the Atlantic.

Within two months, mortgage approvals dropped 31 percent, compared with the previous year. And by March, average housing prices had fallen 2.5 percent, the largest monthly decline since 1992.