And the French , as they did with a second hand A330 from Air Carraibes. ( Sarko one) Discussion at the time was security, speed of availability /dispatch and more important communications. The aircraft , a bit like AF1 , has serious secure comms gear embedded.
The Tanker conversion option was set aside using the argument that in times of tensions or war, the tanker will be used operationally rather than ferrying a head of state around.
But what made the difference of course in the end was the huge ego of Sarkosy at the time. Of course a Falcon 50 or X would do the same at half the cost, but you cannot take than many journalists with you on a Falcon... ( of Which France Government also has a few in addition to the A330)