What about a limited confrontation in Outer Manchuria and northern half of Manchuria along the Amur estuary where Japanese navy and amphibious forces could navigate? Beyond that --- Khalkin Gol was the stepping stone to beyond Manchuria --- would not worth the effort. Regardless of the outcome, Japan was pale in front of the SU for its national power, just like Russia is stronger than Japan today in the OTL. With a limited confrontation in Outer Manchuria and northern half of the Sakhalin island, Japan really need to develop the land. To lessen the strain of the conquered land to support the occupying military, that would mean sizable demilitarization of the forces.
Not to mention, there would be numerous chances of cooperation between Fascist Italy and Japan for crossly improving their equipment. Even then, engaging the SU/Russia in Siberia would not be wise.
Not to mention, there would be numerous chances of cooperation between Fascist Italy and Japan for crossly improving their equipment. Even then, engaging the SU/Russia in Siberia would not be wise.