<Ul> <Li> Blitzkrieg </Li> <Li> Deep operation </Li> <Li> Maneuver warfare </Li> <Li> Operational manoeuvre group </Li> </Ul> <Li> Operational manoeuvre group </Li> <Tr> <Td> Strategy (show) <Ul> <Li> Attrition </Li> <Li> Counter-offensive </Li> <Li> Deception </Li> <Li> Defensive </Li> <Li> Goal </Li> <Li> Naval </Li> <Li> Offensive </Li> </Ul> </Td> </Tr> <Ul> <Li> Attrition </Li> <Li> Counter-offensive </Li> <Li> Deception </Li> <Li> Defensive </Li> <Li> Goal </Li> <Li> Naval </Li> <Li> Offensive </Li> </Ul>

Who was involved in trench warfare during ww1