So I have two recommendations - if you like action + some spying, some romance + bromance/frenemies, check this one out:
(warning: some communist propaganda + female lead that's not great)
https://mydramalist.com/16087-sparrow
- if you like politics, super strong camaraderie/bromance/absolute loyalty towards friends and family + moderate amount of romance + fighting corruption, check this one out:
https://mydramalist.com/10804-all-quiet-in-beijing
If you want to discover more shows on your own, check tags like 'Republican era' or 'World War'