I'm struggling to think of much

I liked Fracture: Life and Culture in the West, 1918-1938 by Philipp Blom but that is more about the culture, mindsets/views and lifestyles of the time rather than an overview of the politics.

It's been a while since I've read it but you could try The Dark Valley: A Panorama of the 1930s by Piers Brendon . It has a little bit on the 20s and then in the 30s it covers each of the major powers with their own chapters. It's pretty long as well