PARIS — The European debt problems that have roiled global financial markets for the last 18 months are showing signs of turning into a far deeper challenge: Europe’s second recession in three years.

Greece, Ireland, Portugal and Spain are already in downturns or fighting to avoid them, as high unemployment and austerity belt-tightening take their toll. But in the last few weeks, even prosperous Germany and France, the Continent’s powerhouses, have started to be dragged down, hurt by the ebbing of business orders from indebted countries in the rest of Europe.

European stocks continued their latest plunge on Tuesday, as the German financial giant Deutsche Bank, buffeted by the debt crisis, reduced its profit forecast for the year. Investors were also jolted by news that the French-Belgian investment bank Dexia might be the region’s first large bank to need a government rescue as a result of the current debt crisis.

It is not just the Continent’s problem.

The United States, a major banking and trading partner with Europe, is stuck in its own rut — prompting the Federal Reserve chairman, Ben S. Bernanke, to warn Tuesday that “the recovery is close to faltering.” He told a Congressional panel that the economy could fall into a new recession unless the government took further action.