But, as the German capital gears up to celebrate 20 years since the fall of the Berlin Wall, leftwing commentators are claiming that capitalism, not communism, is now keeping the two apart.

For the S-Bahn - the suburban commuter railway running into and around Berlin that became a symbol of the cold war divide - has come grinding to a halt.

More than two-thirds of the network's 550 trains were withdrawn from service last week and the main east-west line closed after safety checks following a derailment showed that about 4,000 wheels needed replacing.

Hundreds of thousands of Berliners have been forced to get on their bikes or use alternative, overcrowded routes to work, while tourists weaned on stereotypical notions of German punctuality and efficiency have been left inconvenienced and bemused by the chaos.

Deutsche Bahn, the national railway operator, is under fire for cutting staff and closing repair workshops at its S-Bahn subsidiary in an attempt to boost profitability ahead of an initial public offering, which has since been postponed.

For businesses dependent on the custom of S-Bahn passengers, the partial -suspension of services is no joke.

"For the past two or three days it's been really bad. Customers are down by more than half," said an employee at a clothing-alteration service situated below the deserted S-Bahn platform at Friedrichstrasse station, in the former East Berlin.

"German trains are world famous. I didn't think -something like this could happen."

A columnist for Tagesspiegel, a Berlin-based newspaper, observed that the number of S-Bahn carriages rendered unusable by management incompetence was only slightly fewer than the total damaged by the Red Army in 1945.

Others note that even the Berlin Wall itself did not prevent S-Bahn passengers travelling between west and east, so long as they held a West German passport.

The East German authorities continued to operate the S-Bahn in West Berlin after partition of the city following the second world war until the 1980s. West Berliners eventually boycotted this service in protest at the communist regime.

But now it is being claimed that capitalism is driving passengers away.

"The chaos in the Berliner S-Bahn is a lesson in the consequences of capitalism. It is a graphic depiction of where subservience to financial markets' greedy pursuit of profit ultimately leads," Ulrich Maurer, chief whip of the radical Left party, said.

Deutsche Bahn has apologised for the inconvenience but insists that cost-cutting was not the problem and blames the train manufacturer instead.

"Even if we had had twice as many employees and three times as many workshops . . . it would not have prevented these wheels from breaking," Deutsche Bahn said.

Nevertheless, S-Bahn -Berlin's entire senior management was forced to resign this month after it emerged that they had not ordered sufficient safety checks.

The repairs, refunds and lost fares could leave Deutsche Bahn up to €100m ($142m, £86m) out of pocket, according to one estimate. A full service is not expected to resume until December.