FMGC ; ATC rarely ask you to Go Around. They often order you to do so. In all walks of life, better be armed with a good reason for refusing an order ! I was observer on a big bus into LHR one time when because of the high level of automation, we went to something called mini ground speed (or something like that) when Capt re-selected auto from managed (or something like that - er, I am a simple Boeing driver) ............BUT....... we got awfully close to the preceeding, destroying the immaculate seperation (albeit it tight) by ATC. We got a very clear order.............."AC call sign, GO AROUND, GO AROUND". WE went around.