Tcas
On the Swiss/French UIR Border this morning I heard an a/c at around FL330 report a same level TCAS at 5 miles, the reply was we have nothing on radar, must be military, followed bt a long and fragmented exchange re filing an "Airprox", during which ATC offered to obtain data from other radar sites, the decision was not to file since separation was 5 miles, fine. Imagine my surprise when in the security of Maastricht airspace later in the day when an a/c reported trafic at the same level at 5 miles and the reply was...Nothing on radar it must be military!!
If these returns are genuine military a/c then this is not the right time for un co-ordinated traffic and if they are not then
"BEAM ME SCOTTY"