Pain Management: Military physicians used towards suffering of severe wounds, gassing, and tuberculosis.

Combat Stress and Morale: Alcohol, tobacco, and psychoactive substances used to help soldiers manage physical and emotional pain.

Widespread Addiction: Extensive usage created morphine and other opioid addictions.

Harrison Anti-Narcotics Act of 1914: Aimed to control the distribution of opiates and cocaine.

Colonial Policy: The British military administration continued to use opium monopolies to generate revenue and manage local labor force, importing large quantities to compensate for food shortages.

Source of Morphine: Opium poppies as a source for essential pain-relieving medications, like morphine.

Combat Pharmaceuticals: German military developed a multipurpose drug called SEE administered to injured soldiers on the battlefield for pain reduction and to induce amnesia regarding horrific memories on the battlefield.

Disruption of Trade Routes: The war temporarily closed established, government-controlled opium trade routes extending from Southeast Asia.

Resurgence of Local Cultivation: In response to disruptions, local and illicit opium cultivation continued and prospered in various parts of Asia to meet demand, contributing to the "Golden Triangle".