US influence again?

Just discovered the American Vought ALVRJ (Air Launched Low Volume Ramjet) project that was tested/conducted from 1974-6 with complete success.

For more info;

http://www.vought.com/y73-82/html/alvrj.html

Did this influence the Soviets in designing the Kh-31 ASM which began its life in 1977?

And why did the US NOT pursue this weapon option if it was such a success?

Regards, Glenn.