UNDERGROUND MAN.(Robert Kiley )

A couple of years ago, not long after moving from New York to London, Robert Kiley found himself being toasted by a British diplomat, who said, "You are the most important American to come to Britain since Dwight Eisenhower." This salut may have been excessive: Kiley was London's new transport commissioner; he was not preparing to win a war. Still, great things were expected of him. Londoners were alarmed and depressed by the state of the Underground, their city's subway system, which, after more than fifty years of underinvestment, had fallen into severe decline. The Tube had become crowded, dirty, dangerous, unreliable--while remaining, perhaps even more than New York's subway, crucial to the life of the city. Kiley, as it happened, was the chairman of New York's Metropolitan Transportation Authority from 1983 to 1990--the turnaround years for the subway. Before that, he ran, and dramatically improved, Boston's venerable mass-transit system. And so he had been hired to save the Tube.

Kiley, who is sixty-eight, does have a quietly commanding presence, but, in his dark suits and tortoiseshell glasses, he blends easily into the rows of executives bent over their briefing papers on the Heathrow-Kennedy shuttle. At first, he was even able to ride the Tube without being recognized. There he was struck by the stoicism of his fellow-passengers, who silently endured long delays in airless cars. At Victoria Station, which is forced to close at rush hour nearly every day because of overcrowding, Kiley once found himself caught in a frightening crush. He saw Underground workers form a human chain to hold back a tide of commuters trying to reach the platform. "I'd never seen anything like that anywhere," he told a reporter later. Kiley escaped into a control booth, where the dispatchers worked in full view of the public, and where he thought, We'd be dead by now if we were in Times Square. Here, he said, "there was no complaining. Other than the shuffling of feet, there wasn't much noise."

Simon Jenkins, a former editor of the Times of London, and an influential columnist, is not above complaining. "For millions of working Londoners, the Tube is their only experience of Third World squalor," he has written. "They may not visit London's prisons, mental hospitals, or sweatshops. They may not frequent the ghettos of Hoxton or the tenements of Walworth. They live in tidy homes, work in neat offices, and eat in clean restaurants. But they use the Tube. It is the nastiest thing they do."

Londoners have told me that, if an appointment is important, one must allow forty-five minutes more than a trip should take. Mechanical breakdowns are chronic, and not only on trains. The Tube runs much deeper than the New York subway, and passengers routinely find long lists of stations to avoid because of "escalator problems." One Saturday last year, I found myself carrying a stroller and baby up what felt like a thousand steps. In truth, though, trains and stations are not, as a rule, squalid; some stations are, in fact, splendid. There is graffiti, but it's not oppressive. Kiley has often said that the London Underground is in much better shape than the New York subway was when he took it over.

But London's system is much older than New York's--it opened in 1863, the world's first urban underground train--and it has both its great age and its basic structures to overcome. The deepest lines are fearsomely narrow, with clearances as small as six inches, which precludes air-conditioning in the trains--there would be nowhere for the heat produced by air-conditioners to escape. Its predominantly single-track construction means that lines must be closed for routine maintenance, which is why the Tube does not run past 1 a.m. (New York's twenty-four-hour service relies on extensive double-tracking.) The Tube needs new lines and, more immediately, it needs to run more trains on the lines it has. Deferred maintenance has led to a plague of broken signals, and aging tracks and trains. Derailments are frequent. The last major disaster on the Underground, a fire that started beneath an escalator at King's Cross, killing thirty-one people, was in 1987. But the system is now extremely vulnerable, and everyone knows it.

Kiley's first challenge was not the Tube's dilapidation. It was, rather, political, for a strange and bitter feud had developed around the Underground--a governmental gridlock that threatened Kiley's control of the system he had been hired to fix. Back in 1997, when Tony Blair's Labour Government came to power, it promised to improve the Underground with a "new public-private partnership," or P.P.P. Following a New Labour belief (shared with the Conservatives) that the private sector can build and run almost anything more efficiently than the public sector can, the Blair Government had sharply expanded a Tory program under which contracts to build and maintain schools, hospitals, and prisons were awarded to private companies. These projects had the great short-term political advantage of not showing up in the Treasury's books as public spending. Although Blair had campaigned against a Tory proposal to fully privatize the Tube, he wanted to get as much of the Underground's enormous expense as he possibly could off the government's books.

At the same time, the Blair Government had overseen, as part of its historic commitment to "devolution," the resurrection of independent municipal government in London. The city had not been allowed to govern itself since 1986, when Margaret Thatcher, in an astonishing fit of pique, abolished the Greater London Council. The G.L.C. was at that time led by Ken Livingstone, a flamboyant apostle of working-class leftism known as Red Ken, who used the council to bait Thatcher mercilessly--hanging a huge banner on his headquarters, across from Westminster, advertising the number of jobless Londoners; inviting Sinn Fein to his office in the midst of an I.R.A. bombing campaign. Livingstone was the primary reason that Thatcher got rid of the city's government.