That was made clear Sunday, when at least 18 people were killed in a face-off between members of a local cartel and a Mexican cartel in a frontier zone between Mexico and Guatemala.

CNN: Mexican drug cartels infiltrating Guatemala

It is hard to see what concessions might turn a No into a subsequent Yes: the only conceivable new opt-out is from the Schengen frontier-free travel zone, and that would break up the long-established Nordic passport union.

ECONOMIST: Denmark and the European Union: Still an odd man out? | The