PROFILE: Robert Morgenthau has managed to humble some of the most powerful actors in global finance

In a sense, the second World War never really ended for Mr Robert Morgenthau, the 82-year-old Manhattan district attorney who stunned the financial world this week by indicting Mr Dennis Kozlowski, former chief executive of US conglomerate Tyco.

Mr Morgenthau, scion of a prominent New York family, was serving as an officer on a US destroyer when it was sunk off Algiers by a German torpedo in 1944. Adrift in the Mediterranean, Mr Morgenthau vowed that if he survived he would dedicate his life to public service.

The result has been a government career marked by a taste for battle. Without winning election to an office higher than county prosecutor, Mr Morgenthau has managed to humble some of the most powerful actors in global finance - most notably when his investigation prompted the Bank of England to close the Bank of Credit and Commerce International.

Mr Morgenthau's targets are often like himself - wealthy and well connected. Their crimes generally boil down to a failure to maintain standards - to demonstrate the noblesse oblige that has characterised Mr Morgenthau's own life.

Mr Morgenthau's involvement with Mr Kozlowski is a case in point. The charges involve a private matter - Mr Kozlowski is accused of evading $1 million in taxes on purchases of paintings - but Mr Morgenthau clearly has bigger issues on his mind. He says his interest in Mr Kozlowski stems from Tyco's decision in 1997 to switch its domicile to Bermuda to reduce its taxes.

The indictment also charges Mr Kozlowski with evading taxes after September 11th, when the US was at war - no small matter for an old warrior such as Mr Morgenthau. "I grew up in the World War II environment," he says. "People have to understand that everyone has an obligation to pay their taxes, to support their government - not to spend time thinking about how to get around tax laws."

By the standards of his native New York, Mr Morgenthau was born an aristocrat. His grandfather, a property magnate and philanthropist, was US ambassador to Turkey during the years leading up to the US involvement in the first World War. His father was President Franklin D. Roosevelt's treasury secretary for more than a decade.

Mr Morgenthau's ideological concerns recall those of his father, who served in an administration that sought to rescue capitalism by improving regulation. Even Mr Morgenthau's hostility to offshore tax havens such as Bermuda has precedents in his father's career. In 1937, for example, his father warned Roosevelt that US businessmen were avoiding taxes by setting up personal holding companies in the Bahamas.

Unlike his father, however, Mr Morgenthau has never held high office, though not for lack of effort. In 1962, he ran as the Democratic candidate for governor but he was defeated by Nelson Rockefeller, an even wealthier - and Republican - New Yorker.

Mr Morgenthau has managed to exert global influence despite his lack of political position by employing the considerable powers of the US prosecutor.

He began his career in law enforcement when President John F. Kennedy named him US attorney in Manhattan in 1961. After President Richard Nixon forced him out of that job in 1970, Mr Morgenthau ran for Manhattan district attorney. He got the job in 1975 and has remained in it for 27 years.

The district attorney's office is an unlikely perch for a global activist. Mr Morgenthau's job is to enforce local laws in a limited jurisdiction - one of New York City's five boroughs. But the borough of Manhattan is like no other municipality in the world. It is the centre of the global financial system, with $2,700 billion moving through its banks every day. As the local cop on the beat, as it were, Mr Morgenthau has seen an opportunity to weigh in on weighty matters. "We don't report to the federal government at all - and we do anything we want," he says proudly.

Some critics in local law enforcement wonder whether he is more focused on malfeasance in the upper classes than on common criminals. Indeed, Mr Morgenthau sounds at times less like a local prosecutor than a presumptive treasury secretary or secretary of state. He suggests, for instance, that the British government should do more to help his investigators dig out information in the Cayman Islands, another offshore banking centre.

"London has to tell them what to do; anyone who doesn't think it is run out of London is naive," he says. "Tell them to co-operate with the Manhattan DA."

Mr Morgenthau's ability to conduct such grand activities reflects both the considerable resources of the Manhattan district attorney's office and his own network of contacts. He is assisted by more than 100 investigators and 550 assistant district attorneys. He has more lawyers in Manhattan than such powerhouse Wall Street law firms as Sullivan & Cromwell or Cleary, Gottlieb Steen & Hamilton.

Added to that is a personal contacts list that one former senior Federal Reserve official says has no equal. The halls of justice in New York are filled with judges and senior lawyers who cut their teeth working in Mr Morgenthau's office.

A classic example is Mr Eliot Spitzer, the New York state attorney-general who last month secured an agreement under which Merrill Lynch will pay $100 million to settle conflict of interest allegations against its equity analysts. Mr Spitzer spent six years in Mr Morgenthau's office. "I see Mr Morgenthau as the most senior prosecutor in the nation," Mr Spitzer says. "It's a consequence of his tenure, his stature and the integrity he brings to his office. He is the definition of what law enforcement should be."

Mr Morgenthau also understands that law enforcement has its limits. There is still a part of him that clearly yearns for more influence on policy and financial regulation. "Case making is after the fact. You need more up-front standards and supervision," he says. "There has been a lot of looking the other way - that's why I like the case we just made [against Mr Kozlowski]."

Mr Morgenthau is an old man now. He is hard of hearing and slow of foot. But the Kozlowski case is evidence enough that he has not entertained any ideas of retirement. As he says himself, he has more battles to wage. "I'm too old to retire," he says. "I missed my chance."