(1) Barbarossa was the name for the Nazi attack on the USSR, not the Soviet resistance. (2) Guadalcanal is one word. There's no canal in Guadalcanal, neither the one in the Pacific nor the one in Spain, which derives its name from the Arabic phrase Wadi al-Qanal (وادي القنال), meaning "river of the stalls" or "valley of stalls", referring to the refreshment stalls set up there during the Muslim rule in Andalusia, or so says Wikipedia. (3) On a different note, you might want to tighten up the siege question, since Leningrad would be a correct answer as well. And it's siege of, not on.
I'll fix the Operation Barbarossa, my mistake, as well as Guadalcanal. And I couldn't have put Leningrad, the Soviets didn't necessarily win that battle as the hint states, Nazi Germany simply lifted the siege (872 days after it had started).
Good quiz, but there's a BIG bias here. Apparently 90% of Axis fatalities were on the Eastern front. So the western front was really pretty much just a sideshow to these eastern battles.
I had to include the most well-known encounters of the war, and a few lesser-known ones as well. And yes, but my 'bias' is so that the Average Joe can do decently.
That describes a huge number of battles in the Pacific War.
Maybe "Considered the turning point of the Pacific War" would be a better / less ambiguous clue.