They speak all the languages of the Middle East - and can pass as Islamic extremists to get close to the fanatics they have come to hunt down in Britain. Israel has openly made it clear it fears Britain has become a haven for extremist preachers and their network of organisations dedicated to sowing hatred.
I think this is the key point of the entire article, who are they going to trust. Is that new recruit real, or an agent?
If one of your men dies in an auto accident, was it real or the Mossad?
Psy-war at its best.