US immigration pre-clearance is extended in Europe, North Asia, and Caribbean, but at what cost?

Towards the end of 2014 there was much chatter in the media about the prospect of more airports in Europe offering immigration pre-clearance for the United States and that this had emerged through an initiative by the US Department of Homeland Security (DHS). Pre-clearance arrangements, which are already in place for flights from Canada, the Caribbean, one city in the Gulf and (in Europe) two airports in Ireland, are designed to ease congestion at US airports and are not supposed to represent a security imperative.

However, the fact that the initiative came from the Department whose job it is to keep the US secure from internal and external threats does suggest that counter-terrorism needs were driving the process rather more than queues at US airports. There are other equally pressing issues. While many airports favour these arrangements there is evidence that passengers are not getting some of the benefits they might have expected.