A couple of things spring to my inexpert mind here. First, if there is a no-fly zone but a country has airliners flying into and out then would I be wrong to think that those airliners (of whatever nationality) have specific routings, height maintenance and timings? Second, is the way the alleged UN aircraft identified itself correct for such an intercept? Third, the tone of the report is very biased and it is good that someone else on the List has identified the author as a pro-Saddam individual. Fourth, and finally, that the bulk of UN aircraft are currently US/UK is a matter of record - however, most other UN nations with appropriate military expertise are making their agreed contribution to the general effort which is a UN effort.
