Operation Frantic was “joint” in the sense we used Soviet bases with their support but it had only limited success and did not last long. So yeah, not much joint history there.
I always saw WWII as 3 separate wars. We never really fought “side by side” US vs Japan. US/France/UK versus the Germany/Italy and USSR and their war on the Eastern Front.
It seemed like we intentionally kept our battle zones apart. Remember one of the Doolittle bombers landed in the USSR, and he wasn’t returned until after the war.
I didn’t know about Operation Frantic.