Talk about adding insult to injury. Thanks to the credit crisis and the slump in the dollar, foreign investors in US companies have had their fingers burned – or if the investment was in banking, their arms ripped off and the bleeding stumps cauterised. Yet far from desperately trying to reassure foreign investors not to pull out, the US Treasury now seems likely to tighten the rules on foreigners taking stakes in US companies.

Rather like introducing a bouncer and a guest list for a deserted nightclub, perhaps the new rules will succeed in creating a sense of exclusivity. Do not bet on it.