If you are convinced that EU officials deliberately spend a great deal of their time talking gobbledygook, this is the phrase to pull out to prove you are right. A semi-official term in EU corridors of power, constructive ambiguity means phrasing an idea in such a vague way that no one is quite sure what is being said. It is a useful diplomatic device that allows EU decisions to be interpreted in different ways in different countries. If you have ever wondered how what was apparently the same decision taken by EU ministers in Brussels can be presented in such different and seemingly opposing ways when said ministers get home, blame constructive ambiguity. And of course, spin. While often used in the EU, constructive ambiguity is an essential tool of modern diplomacy.