At last year's meeting of the Group of Eight rich countries in Germany, leaders issued a strident call against what they referred to as "investment protectionism". It was a statement that took on an increasingly hollow ring as the months wore on. Usually regarded as a trait of developing countries suspicious of western-based multinational corporations, scepticism about foreign direct investment (FDI) now appears to be spreading among the rich nations.

A succession of developed countries have recently tightened up their laws and declared high-profile assets off-limits to foreign investors. Nor does this simply reflect suspicion of sovereign wealth funds from oil-rich autocracies. Stable, mature democracies are blocking public and private investments from each other.