I'd like to know who are behind these terrorists - we may have identified the 'foot soldiers' but who is organising them?  They won't have entered the country, nor entered Europe, as illegal immigrants and no doubt as soon as an attack has occurred will have left the area.

There has to be an organisation that coordinated the recent attacks but we hear nothing about them.

As for the idea of 'closing' borders nobody has offered a reasonable method of keeping out potential terrorists who enter the country as tourists, business travellers or students.  How is it physically possible to thoroughly vet each traveller without making our airports and seaports grind to a halt?

The really dangerous individuals aren't going to enter the country hidden in the back of a lorry, far more likely to be wearing a suit and travelling business class.