Hm, which would be the weakest link? Tunisia?
The plane just disappeared from radar at 37,000 ft. No descent data. It’s there then it’s gone. This suggests a breakup of the aircraft at altitude. Mechanical fault or bomb?
The plane was coming and going from Paris. Terrorism? A time bomb could have been placed in a well hidden place while it was in Eritrea or Tunisia, set to go off hours and several flights later. Who knows?