FRANKFURT — Deutsche Bank embarked Sunday on what may be its last chance to reverse a decade of decline, announcing that it would cut a fifth of its work force and slash operations in New York and London.

The reorganization and cost-cutting plan is reminiscent of the bloodletting that followed the financial crisis in 2008. Yet it comes at a time of relative prosperity, the cumulative effect of years of scandal and management missteps. The bank that once symbolized German economic prowess is effectively abandoning any hope of playing in the same league as Goldman Sachs or JPMorgan Chase, and struggling simply to remain relevant.

Ever since it planted its flag on Wall Street by acquiring Bankers Trust in 1999, Deutsche Bank has been trying to prove that global finance was not the exclusive territory of the American megabanks. But it did so by taking chances, including issuing hundreds of billions of dollars in high-risk derivatives and lending money to Donald J. Trump’s organization when other banks wouldn’t.

The financial crisis that began in 2008 exposed a history of sometimes criminal wrongdoing, including rigging interest rates, laundering money and violating United States sanctions against countries like Iran. The scandals, which persisted long past the crisis, eroded Deutsche Bank’s reputation and led to billions of dollars in fines. Regulators anxious to avoid any more financial crises forced Deutsche Bank and other lenders to take fewer risks.