I have a question. Where is Japan? The world leaders and accompanying media hordes heading this weekend for the shores of Lake Toya need not turn to their atlases. The question is one of psychology rather than geography. Japan is still the world’s second most powerful economy. Politically, it is all but invisible.

Next week’s Toyako summit of the Group of Eight leading industrial nations promises a rare moment in the sun. Prime ministers and presidents will pronounce on everything from oil prices and global warming to nuclear proliferation and the fight against malaria. As many as 14 leaders from emerging powers will make cameo appearances. Lunch with the Chinese, coffee with the Senegalese?

The international media will devour every inconsequential cough and comma. Summit host Yasuo Fukuda will appear on front pages from Berlin to Buenos Aires. When it is all over Japan can slip back into the shadows.

The summit sherpas say we should expect nothing of great significance, though their political bosses must insist otherwise. Japan’s preparations have won few plaudits. Ponderous planning has sometimes revealed as many divisions among ministries in Tokyo as among other capitals.

The goal is consensus: better bland accord than public discord. Others in the G8 have used their summits to promote pet projects – Britain trumpeted aid for Africa, Germany climate change. Japan seems to lack any burning priorities.

This is all of a piece with its barely visible profile in the global arena. I spend a fair part of my life on the international conference circuit. Never before have governments – of rising as well as mature powers – devoted as much time to peering into their crystal balls in search of a new geopolitical landscape. By and large – I can think of one recent exception – Japan is absent from such events. What is more, Japan’s place in the new order rarely merits mention by its peers.

Scroll back to the late 1980s. Japan was the rising power. Academics and journalists fell over themselves in the rush to predict that its economic might was destined to eclipse that of the US. When foreign policy experts declared that the 21st century would belong to Asia, they were not thinking about China and India.

Politicians in Washington fulminated as Japanese companies snapped up such American icons as New York’s Rockefeller Center and Hollywood’s Columbia Pictures. US motorists swapped their Fords and Chevrolets for Toyotas.

And now? Well, western consumers still buy Toyotas; and Sony and Toshiba continue to produce all manner of electronic wizardry. But Japan has become an afterthought in the discourse about the fast-shifting balance of global power. The Asian century is about China and India.

There are some obvious explanations for this reversal. More often than not political presence mirrors economic performance. Before the ink was properly dry on those forecasts of an ineluctable march to economic hegemony, Japan entered the great deflation of the 1990s. The asset price bubble burst, banks went bankrupt and the economy went into free fall. Japan lost a decade.

The economy has regained its balance, though its growth rate remains low. An ageing and shrinking population holds little prospect of a return to the dynamism of the 1980s. For all that, Japan’s disorientation is about more than the miscalculations of economic policymakers. Financial implosion robbed politicians of their confidence; the collapse of the Soviet Union remade Japan’s geopolitical co-ordinates.

The aftermath of the second world war and the ensuing cold war with communism hitched Japan firmly to the US and Europe. Geography played second fiddle to ideology. A US security guarantee filled the gap left by the tight constitutional constraints on Japan’s own military.

For all intents and purposes, this Japan was part of the west. It might have seemed different and, sometimes, economically threatening. But it was an ally against communism, like Europe sheltering under the US nuclear umbrella, and provided an Asian pillar for the market economy.

Just as the collapse of the Soviet Union weakened the glue in the transatlantic alliance, so it put a question mark over Japan’s long-term relationship with Washington. The re-emergence of China then amplified the uncertainties. If the speed of China’s rise has disconcerted Americans and Europeans, it has terrified Japan.

You can see why. This is a relationship steeped in historical rancour. Nationalist rivalries are never more than an inch below the surface. In two or three years China will displace Japan as America’s closest economic rival. Within a decade it may have toppled the US as the pre-eminent power in east Asia.

Japan’s reflex response has been to draw closer to the US. But China’s rise also forces it to face up to an Asian identity it has always shunned. A few weeks back, Mr Fukuda tried to square the circle by turning a page in the atlas. Japan, he said, should be seen in the context not of east Asia but of the much greater number of nations bordering the Pacific. This community bound Japan to the US, Australia and New Zealand as well as to the countries of south-east Asia, China and Russia. It was a nice try, but to my mind dodged my question.

Some would say there is no answer. Japan confronts many overlapping options. It is patching up relations with Beijing after a dangerous confrontation in 2005. Simultaneously, it wants Washington to do more to contain China. A US presidential victory for the Republican, John McCain, could hold out the prospect of a new alliance of Australasian democracies. Japan, meanwhile, could abandon the constraints on its own military.

The most cogent answer I have heard is from a young Japanese diplomat who posits that his country’s natural role is as a bridge between Asia and the west and between mature and rising powers. In this guise Japan would act as a stabiliser in a region that would otherwise be dominated by China: friends with Beijing but also balancing it.

For what it is worth, I think that Japan’s pre-eminent interest lies in working to extend and strengthen the rules-based international order to draw in China and other rising powers. More than anything else, this part of the world needs a robust mutual security system.

As things stand, Japan looks like a nation without a compass. All of the choices mentioned above require decisions about its identity. Now there is something to ponder as the sun sets on Lake Toya.

philip.stephens@ft.com

More columns at www.ft.com/philipstephens