As the financial crisis bites deep into the bones of the global economy, a new passion is taking hold in Downing Street and the White House. It's a new war against offshore tax havens that have been enjoyed by entrepreneurs and multinationals for many decades.

Yesterday's Observer reports that some £8.2 trillion of private wealth sits in tax havens, costing home governments £180bn - £25bn of which is lost to HM Treasury.

How ironic that Gordon Brown and Barack Obama should want a piece of that action now. Two years ago, you could have done a lot with £25bn or £180bn. Now it will hardly bail out a reasonably-sized bank.

But Brown is on the warpath: he asked Congress, how much safer would people's savings be "if the whole world finally came together to outlaw shadow banking systems and offshore tax havens".

Obama is, too, viz, the "Stop Tax Haven Abuse Act" - which is currently a bill. (And don't forget that this wouldn't be the first time that America went to war over tax matters!)

So - they're happy to slag off the "shadow" banking systems, while in fact it's the banking systems that operated in the full glare of publicity that seem to be falling to pieces.

Be that as it may, expect the agenda to shift from fighting against "the axis of evil" to "the taxes of evil" - and remember you first heard that phrase here!