It was during the Vietnam War and the government hoped to harness weather to increase rainfall and prevent the Vietnamese from obtaining supplies. They hoped to accomplish this by washing out river crossings and even causing landslides. The government began seeding clouds with silver and lead iodide. The result was a success and they were able to extend the monsoon period, but all the rainfall flooded the Song Con River resulting in the failure of Operation Ivory Coast. Operation Popeye is known as one fo the first examples of attempted weather modification by the government.