There are few more forlorn and pointless occupations in the world than that of the Japanese riot police. Consider their situation - plucked from the ranks for their intelligence and fitness, trained over several years in marksmanship, crowd control and the most lethal of the martial arts, then set loose in a country with the same level of civil unrest as Legoland.

Forty years ago Tokyo was a place of crunchy anti-American protests; these days the closest you get to a rampaging mob in Tokyo is sale time at Prada. “Japanese riot policeman” is close to being a contradiction in terms, like Welsh humorist or Scottish gourmet. So it seems only fair that, every now and then, Japan's finest are allowed out of their box.

So they were last week, at the G8 summit on the northern island of Hokkaido. On the face of it, this was an opportunity for the world's most powerful leaders to come together to discuss weighty issues of global import. In fact, it was a poorly disguised excuse for rozzers from all over Japan to unite for the riot policing equivalent of a three-day bender.

The leaders of the US, Britain, Germany and Russia all in one room are certainly a succulent terrorist target. The Japanese strategy was to locate the room on top of a mountain and seal it off for 30 miles in every direction. Filling the void, in patrol cars, buses and on foot, equipped with body armour, riot shields, perspex shields, guns and smiles, were 20,000 police.

The scene on the road to the media centre was like one of those post-holocaust scenarios when the human beings have died out, bequeathing the Earth to the cockroaches - except that these cockroaches were blue, life-size and carrying truncheons. Every hundred yards, for an hour-long drive, was a Plod standing on an almost empty road, with literally nothing to do.

Now it is true that the summit went off without a single security hitch. George Bush returned home unassassinated and at no point were Gordon Brown or Angel Merkel dressed up in orange jumpsuits and offered in return for the release of al-Qaeda militants. On the other hand, the policing bill for the three days was 30 billion yen. That's £142 million. That's £47 million a day, £2 million an hour, £33,000 a minute.

Something about police saturation of that intensity has the curious effect of making me feel both irritable and guilty - if there are so many police around here, I find myself reasoning, I must have done something wrong. Conspiracy to jaywalk? Nope. Snacking between meals in a built-up area? Not me. Sneering, cynical attitude to the forces of law and order? It's a fair cop, guv. Slap on the cuffs.

Not so camp

Disappointingly, the police presence was unmatched by what has become a traditional element of international jamborees such as the G8 - anti-globalisation protesters. The authorities had set up two small camps in inaccessible rural spots, impossibly far from the summit itself. Just to be on the safe side, they also deported a few dozen foreigners suspected of harbouring anti-G8 sentiments. Those who made it through were confronted with a still more insurmountable obstacle - the Japanese disinclination to organised self-assertion and mass protest.

The most touching example of this is Tokyo's annual Gay Pride event, which would be more accurately named the Gay Diffidence Parade - a few hundred polite and apologetic looking gays and lesbians, singing songs with lyrics such as Tom Robinson's “Sing If You're A Little Bit Bashful About Being Gay”. The same goes for the anti-globalisation movement. A colleague who made the journey to one of the G8 protest camps reported a culture clash between visiting Dutch and German anarchists (facial tattoos, ferocious dedication to the overthrow of the coercive state, etc) and their Japanese counterparts - well-meaning young people with clipboards who simply wanted to get the whole thing organised.

Who's that man?

The G8 summit also serves as a useful barometer of the charisma of Japanese prime ministers. In the old days the Japanese Prime Minister was inevitably the little fellow whose name you couldn't remember, standing rather uncomfortably at the edge of the edge of the group photograph. Then came the eccentric Junichiro Koizumi - everyone remembered him, with his billowing perm, beaming self-confidence and love of Elvis Presley. His successor, Mr Abe, was so unmemorable, however, that when the anti-globalisation protesters created grotesque heads of each of the leaders, they didn't even bother making an Abe one, and used the previous year's Koizumi mask.

Yasuo Fukuda, who oversaw last week's event, has a different problem: foreign journalists seem unable to spell his name. The past month has seen multiple Yasous, Yusuos, Fakudas, Fukadas and even a Fukudu.

But there is no excuse for not remembering his face - viewed from the right angle, with the light falling on his broad upper lip, he is the doppelganger of Homer Simpson.

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