Originally Posted by
Shaggy Sheep Driver
The Americans tried variations on this with their proposed SSTs and failed miserably.
To be fair, the reason why the American SST programme became unaffordable was that they targeted Mach 3 rather than Mach2(ish). The airframe temperatures at Mach 3 are higher, which drove materials (and other) requirements that were uneconomic and that's why they abandoned the project.
If you want to cite a "clever" US/Europe discriminator I think it would have been identifying that Mach 2.2 was the economic sweet-spot rather than any airframe configuration issues per se.
PDR