I mean, WWI and WWII. Do you think of the years of 1914-1945 as one big conflict interrupted by a truce as opposed to two separate wars that were fought in the first 50-years of the 20th century?
Personally, I tend too.
I do think the one directly gave birth to the other. WW1 was about empires and alliances and it gave birth to WW2 which was about totalitariam empires and their (in Germanies certainly) perception that they had not really lost ww1 but had somehow been betrayed, undefeated on the battlefield.