Emu regiments supported by shock Cassowary battalions and wombat-drawn artillery.
It was impossible for the Japanese to come anywhere close to invading Australia, it could have been possible if that was all they focused on after 1931 and didn't bother invading China.
If by "drawing off" you mean requiring the greatest amount of manpower/resources to kill people, I suppose you are right. If the Soviets had been compelled to fight on two fronts (as the Americans were) they might not have been able to do it. As it was, they were throwing everything they had at the Germans, who already held a big chunk of their western territory.
But the Soviets thrashed the Japanese in 1938 and 1939. And funnily enough the Japanese signed their non-aggression pact only months before Barbarossa (though not as funny as the lack of cooperation between the North Koreans and the Chinese). Khalkhin Gol led directly to Pearl Harbor.
You have to love the twists history takes.
An act of mercy at the battle at Marcoing saved Hitler's life.
Talvisota led directly to Hitler deciding launch Barbarossa.
A would be Russian poet was wounded in the Battle of Bryansk which led him to design the most iconic weapon of the 20th century.
Anybody here remember the series
Connections by Jame Burke (or his follow up
The day the Universe Changed)?