Haughtney,
Nothing is black and white in this world.You might think that English only ATC is the safest and logic is certainly on your side.However,there are circumstances where an ATCO can more easily manage a situation by addressing an aircraft in their common native tongue,and vice-versa.
How many missed calls or incorrrect readbacks do we hear on the radio every day?Do you really think the average pilot can derive good situational awareness by listening to the commands given to other traffic?They might hear but do they listen?At busy airports,crews have enough on their plate just getting their own taxi instructions right.Whilst a good crew will monitor other calls,can they really derive good SA all of the time by doing so?
Position and hold and takeoff clearances on a runway with both intersection/full length departures should be done in ENGLISH I agree.Same goes for takeoff/landing clearances on intersecting runways(good example is the old layout at BCN).
The reality is that trust between an ATCO and a pilot is implicit.Additionally,we have TCAS and they have their computer backups too.Pilots can help ATCO's in all kinds of ways and they should really do so when at all possible.Unfortunately,some dont just to make a point.And ATCO's can help pilots above and beyond separation as well(EAL401 might have been saved by a sharp ATCO).
Finally,and it has to be said I'm afraid;a lot of Brits(and maybe a few Yanks) go to these far flung places expecting the ATC to be like blightey/uncle Sam.It is different;you cant colloquialize,the tempo's unfamiliar and you will hear other languages.But if you remember that the worst disaster in aviation history happened on the ground and everybody was communicating in English at the time,then you will realise that nothing in life is for sure.If you do x,you will get y.Well..maybe,maybe not.