Bullet trains streaking past Mount Fuji have provided some of the defining images of postwar Japan. TGVs hurtling through vineyards and along the Côte d'Azur have done the same for France. If Britain has an equivalent it is the gleaming Eurostar terminus at St Pancras International - with this depressing difference: the TGV and Shinkansen networks are embedded in their countries' economies, self-images and daily lives. St Pancras International is the end of a 68-mile, £7 billion stub.

The Channel Tunnel Rail Link ends in North London because it was meant to connect the whole country, not just the capital, to Europe's high speed rail network. This week Tom Harris, the Rail Minister, poured cold water on the idea of building more high-speed lines to Scotland and the North. He said the environmental case was weak and argued that Britain's “economic geography” was unsuitable. His wrongheadedness is matched only by his narrowness of vision. This country may not be able to commit itself to putting anyone in space, but it should commit itself to bringing Glasgow within three hours by train of London - and within five of Paris.

The long-term case for British bullet trains is irresistible. The country's existing intercity network is overcrowded, unreliable and growing much slower than demand. When vital engineering works overrun, as they have three times this year on the West Coast Main Line alone, tens of thousands suffer. Those works are part of an effort to boost national rail capacity by 22.5 per cent in five years, but the total distance travelled by passengers in that period will grow nearly three times as fast.

New high-speed lines linking London with Glasgow via Birmingham and Manchester and Edinburgh via the North East would solve this looming capacity crunch. By bringing the main urban centres of the North up to a third closer to London in terms of journey times they would also transform the economic geography that Mr Willis cites as an excuse for inaction.

Southeastern England is, for better or worse, the engine of the UK economy. The rest of the country needs to be bound closer to it. Air travel cannot achieve this. Nor can Britain's already clogged motorways, but a step change in rail capacity could: one recent analysis based on a new high-speed network costing £31 billion found economic benefits worth more than twice as much over the period it would take to build.

The environmental case for high-speed rail is scarcely less compelling. The per-passenger-mile carbon cost of trains travelling at 186 mph is higher than for most current British intercity services, but barely a tenth as high as for the short-haul flights with which these trains compete. And the European experience, including that of Eurostar, is that given this choice passengers overwhelmingly take the train.

It is true that budget overruns on the High-Speed Rail Link will have alarmed potential investors, but that line was uniquely expensive because so much of it is underground. It is also true that ours is a crowded island, but a 21st-century rail network, built as far as possible alongside existing motorways, would ease rather than intensify the crush.

Mr Willis has said Britain's transport challenges are “congestion and reliability, not journey times”. He sets his sights embarrassingly low. Like France and Japan, this is a developed country. It needs to move - and fast.