Last March, for example, many observers – including myself – thought the implosion of Bear Stearns might mark the worst moment of financial stress. Then, when Lehman Brothers tumbled in mid-September, some investors thought this marked another nadir.

But now we know these were merely preludes to an even more extraordinary drama that has convulsed the financial system in recent days. Never mind the (oft-quoted) suggestion that we are witnessing the worst crisis since the 1930s. Some of the more gloomy – and geeky – policymakers who assembled in Washington last weekend now think we need to reach further back for parallels, such as to 1914, when the onset of war sparked banking panic.

Yet, while such parallels might now look terrifying, they also – perversely – contain the seeds of real hope. For while last weekend's Washington meeting did not produce what some investors desperately wanted to see – namely a blanket guarantee for all interbank lending – it did offer something else: an end to official policy denial. Most notably, there is now a clear consensus among western policy leaders that they cannot continue to pretend the current banking dramas are merely about liquidity.