Another mitigating factor is that Turkey does not trade with many other emerging-market countries.

"It's an example of how Brazil and other emerging-market countries would be well advised not to make themselves so dependent on short-term capital."

Still, the deal was expensive, although Argentina can get a better deal than other emerging-market countries.

Prices fall for commodities, on which many emerging-market countries also depend for economic growth.

This group was formed to bring together established industrial and emerging-market countries from all regions of the world.

So were exchange-rate shifts and swings in commodity prices that made some emerging-market countries more competitive abroad.

Such a withdrawal could create a new round of market instability and raise the cost of borrowing for all emerging-market countries, damaging them further.

All this capital made a spectacular difference to emerging-market countries.

One is that the cost of borrowing, a big burden on emerging-market countries, may decline.

The other is that the American economy is more likely to rebound quickly, reviving the market for exports, especially commodities, from emerging-market countries.