1. Trench Warfare: The war largely involved fighting from entrenched positions, and poison gas was seen as a means to break enemy lines. Its ability to spread over significant distances and linger on the ground could force soldiers out of their trenches or even cause extensive casualties without the need for direct ground combat.
2. Area Denial: Poison gas could be used to create zones of contamination that became impassable for enemy troops. This could create obstacles to enemy movements and force them into less advantageous positions.
3. Psychological Impact: The use of poison gas, particularly new and unpredictable agents like mustard gas, played a significant role in undermining the morale of enemy soldiers and civilians. The fear and uncertainty caused by chemical warfare could lead to loss of troop cohesion and desertions.
4. Surprise and Speed: Poison gas could exploit gaps or vulnerabilities in the enemy's defense, allowing for quick advances. In certain cases, it facilitated the capture of enemy positions.
5. Strategic Goals: Poison gas offered options for achieving strategic goals by targeting logistical areas, supply routes, and industrial centers behind the frontlines. By spreading chaos and disruption, it also aimed to weaken an opponent's civilian support for the war effort.
The extensive use of poison gas in World War I raised serious concerns about the morality and long-term effects of chemical warfare. This eventually led to the signing of the Geneva Protocol of 1925, which aimed to prohibit the use of poison gas and bacteriological weapons in warfare.