Multiple choice Why did the conflict grow to involve all major European countries? (WWI) They all wanted to control Serbia for it’s resources The series of alliances formed previous to WWI They all hated Germany They needed to reactivate the economy with a war Reveal answer Fill a bubble to check yourself B Correct answer Explanation The complex web of mutual defense treaties and alliances meant that a localized conflict between Austria-Hungary and Serbia triggered a chain reaction, pulling in all major European powers.