Answer:
They were primarily used to demoralize, injure, and kill entrenched defenders, against whom the indiscriminate and generally very slow-moving or static nature of gas clouds would be most effective.
Explanation:
Mustard gas, introduced by the Germans in 1917, blistered the skin, eyes, and lungs, and killed thousands. Military strategists defended the use of poison gas by saying it reduced the enemy's ability to respond and thus saved lives in offensives.
