Emerging markets lose their allure for investors

New York

IN Russia, it's assassinations and war. In Brazil, a corruption scandal may derail the economy. And in Turkey, the president is attacking the country's senior central banker.

Emerging markets, not long ago seen as a necessary ingredient for the common portfolio, have lately taken on a more toxic quality as messy politics and staggering economies are prompting some investors to reassess their investment rationale.

Compounding these concerns has been the dollar's upward march and the growing acceptance that the Federal Reserve will soon increase interest rates as the United States economy outpaces the rest of the world's.

Emerging-market currencies, an accurate barometer of investor mood swings, are now suffering the consequences. The Turkish lira and the Brazilian real have touched multi-year lows against the dollar whil…