大象传媒

There are a lot of hard sums being done in Washington at the moment - the math as they put it there. With banks using up tax-payers' money like it's about to go out of fashion, and a recession biting by the day, the deficit in the public finances widens into an ocean of red ink in the coming years.

Mr Obama has just spotted where some of that money could come from. Echoing the G20 leaders, he identified tax-havens as culprits that need to be clobbered, though he and they don't quite put it that way.

It might be hard to do, though, or so thinks David Cay Johnston who won a string of awards and even one change in the law when he reported on tax for the New York Times. Now, he teaches law at Syracuse University in New York State. He told Lesley Curwen that tax havens should now be nervous.