I find the parallels with the 20's and 30's to be existentially threatening in the age of rapid climate change and nuclear weapons.
As the new-old adage goes, history doesn't repeat but it does rhyme.
1930s Great Depression = 21C Great Recession
1930s Fascism & Communism = 21C Alt-Right & "alt-Left"
World War 2 = World Troubles/The Great Troubles?
ICYMI, a World Troubles/Great Troubles is just like what happened in Northern Ireland in the last third of the 20C, but on a global scale - more violent than what's happening now, but still not violent enough for formal declarations of war. Instead of an Allies vs Axis conflict, it'll likely be between globalised non-state actors, with government forces struggling to maintain the peace.
I wager a World Troubles/Great Troubles would be far more likely than WW3, because the atom bomb made traditional conventional war obsolete, and last I checked, the Nuclear Club is still sticking to a "no first use" policy.