From what i've read drag coefficient at mach 1 is several times (up to 10x) the drag coefficient below drag divergence mach number. It drops as the mach number increases.
It's easy to find plots representing experimental data for Cd vs M, but I wonder what's the relationship between drag FORCE and mach number. I wasn't able to find a plot for this. I wonder if an aircraft that can reach Mach 1 can automatically reach say mach 1.2, given that even though Cd drops the drag still increases with the square of speed (and engine power required is cubed)