<Ul> <Li> Armor </Li> <Li> Artillery </Li> <Li> Biological </Li> <Li> Cavalry </Li> <Li> Chemical </Li> <Li> Conventional </Li> <Li> Cyber </Li> <Li> Electronic </Li> <Li> Infantry </Li> <Li> Nuclear </Li> <Li> Psychological </Li> <Li> Unconventional </Li> </Ul> <Tr> <Td> Tactics (show) <Ul> <Li> Aerial </Li> <Li> Battle </Li> <Li> Cavalry </Li> <Li> Charge </Li> <Li> Counterattack </Li> <Li> Counter-insurgency </Li> <Li> Cover </Li> <Li> Foxhole </Li> <Li> Guerrilla warfare </Li> <Li> Morale </Li> <Li> Siege </Li> <Li> Swarming </Li> <Li> Tactical objective </Li> <Li> Trench warfare </Li> </Ul> </Td> </Tr> <Ul> <Li> Aerial </Li> <Li> Battle </Li> <Li> Cavalry </Li> <Li> Charge </Li> <Li> Counterattack </Li> <Li> Counter-insurgency </Li> <Li> Cover </Li> <Li> Foxhole </Li> <Li> Guerrilla warfare </Li> <Li> Morale </Li> <Li> Siege </Li> <Li> Swarming </Li> <Li> Tactical objective </Li> <Li> Trench warfare </Li> </Ul> <Tr> <Td> Operational (show) <Ul> <Li> Blitzkrieg </Li> <Li> Deep operation </Li> <Li> Maneuver warfare </Li> <Li> Operational manoeuvre group </Li> </Ul> </Td> </Tr>

Who was involved in world war 1 trench warfare