If this was a missile, how come no one has said they heard it?
Btw A4 I agree with what you written, that trajectory does reminds me of an SLBM or a ICBM launch.
I am not saying I think its the French, I am just using this video to illustrate that it looks liked a SLBM launch, Its probably not. It just that it looks like one.
A missile would have been moving much more rapidly and the angle is a bit 'flat' to be a space-bound rocket/ICBM/SLBM, it would be much more vertical if it was one of those. With the international notifications and NOTAMs that would have to put out about it would be pretty hard to slip a launch like that by, and if it wasn't ours a whole slew of US sensors would have lit up warning us.
Nothing to see here folks, the flash of light you saw in the sky was not a missile. Swamp gas from a weather balloon was trapped in a thermal pocket and reflected the light from Venus. Now just look into this light.......