Anyone who's ever been to Dubai will know that Emiratis love to shop. But when it comes to buying-up big Western businesses, ‘Dubai plc' is not always a welcome customer.

Last year, Dubai ports operator, DP World was left exasperated in its bid for P&O. In a lengthy acquisition process, it was forced to agree to sell off the US parts as a condition of acquiring P&O in the end, after US senators mounted a high profile scare campaign about "Arab" control of US ports.