I'm going to list two common arguments, that in my view, are logically mutually exclusive, and shouldn't be held by the same person. Let me know which of the two views you hold, or if you believe you can reconcile them.
A) Often with a perspective focused on Versailles and the settlement of WWI, focused on its structural flaws (German dissatisfaction, end of Allied unity, US and Soviet isolation), a second European war of German revenge is seen as the most probable and difficult to deflect outcome.
Oh yeah... by 1930, every German boy had heard so much about the fun of trench warfare that they wanted to try it themselves. Not!
Whatever resentment Germans felt over Versailles, it was lot less than the trauma of the war - millions of men killed and mutilated, the nation's wealth exhausted, ending in starvation on the home front. (The repulsive concoctions which served as ersatz food and drink in 1917-1918 would discourage any warmonger.)
B) Often with a perspective focused on European popular opinion and universal dread of war among Allied, American, Italian and German publics, and the unique role of Hitler, WWII is portrayed as a freak event that no one except Hitler wanted.
Not quite true, but it took Hitler's messianic recklessness and absolute power to take Germany to war. The further involvement of Italy was due to the arrogance and folly of Mussolini (and the early success of Germany); the involvement of Japan was due to the mania of the Japanese militarist cult.
C) Some combination of the two.
A - not true, B - true. C - not logically possible.
But D - a second World War could have been initiated by a power other than Germany. Specifically, the USSR. I don't believe the USSR would have remained quiescent forever.
By 1939, the USSR had built up the largest land and air forces in the world. It's argued that this was only because of Germany's build-up under Hitler, but the USSR viewed itself as the base of revolutionary war against all non-socialist governments. In the 1920s and 1930s the USSR was too weak for open war, and by 1940 was checked by Germany.
If there was no "Third Reich", Germany and the Western powers would have been far less armed than OTL, and sooner or later the USSR would try something. A Soviet-Japanese alliance may seem improbable, but no more so than the Soviet-Nazi alliance of OTL. One could also see the USSR taking advantage of anti-colonial unrest in the Middle East and India.
All this could happen in the mid 1940s.