Few individuals are capable of seeing clearly how they appear to others. Politicians and the peoples they represent tend to be equally blind. Nostalgia for past glories or mistaken memories cloud their vision. We all need a dose of realism

Prime Minister Theresa May's Jan. 17 speech on Brexit was more realistic than some recent statements by British ministers. She set out what Britain wanted to achieve and stressed that Britain was not trying to undermine the European Union. But it took little account of what the other 27 member countries want from the negotiations or the difficulties facing the EU.

In any negotiations one party can always walk away, if the deal is not considered good enough, but it was neither necessary nor wise to spell this out as May did. The danger with making threats, which if carried out could seriously damage Britain's long-term interests, is that the threats may be regarded as bluff, which the EU may be tempted to call.