@baggersup...
Unfortunately the Americans have yet to learn the lessons of Europe in the 60's / 70's / 80's / 90's... We lived with the threat of terrorism from the IRA, Baader Mienhof, PLO and Brigado Rosso et al. If you let these people change your way of life then they have won. Life must continue as close to possible as normal.
@jackonicko
Numbers of diplomats in a country's mission are the subject of bilateral agreement. Although the odd trade attaché may not be all he appears to be it is rather difficult to hide 22 intelligence operatives within the normal diplomatic staff. Any member of the agreed diplomatic staff who enjoys immunity that is caught in activities inconsistent with diplomatic position will be expelled. That of course will trigger a tit-for-tat expulsion on the other side to protest their innocence...... And so on.....
Of course what you get away with on the pretext of the USA's 'War Of Terror' in partership with local LEA's is quite another thing.