Differences between 征, 伐, 讨, 侵, 袭? These characters all mean "to attack" or "to invade", but what are the differences between them? When should one be used and not the others?
it is hard to tell what they exactly mean without contexts, but i can give you a very general idea of these characters:

征 (zheng1) means 'wage war by travelling a long distance'. it is usually associated with a war with a very large scale in both space and time.

伐 (fa2) is just 'to wage war against', nothing more. in fact, among all five characters, only the original meaning of 伐 is directly related with war.

讨 (tao3), literally "to demand", means "to wage war demanding justice/punish the wrongdoers"

侵 (qin1) means “to invade" or "to encroach"

袭 (xi2) is usually associated with “sudden attack”.