I found this article and what I read shocked me.
There are an estimated 650,000 like Hong Hanh in Vietnam, suffering from an array of baffling chronic conditions. Another 500,000 have already died. The thread that weaves through all their case histories is defoliants deployed by the US military during the war. Some of the victims are veterans who were doused in these chemicals during the war, others are farmers who lived off land that was sprayed. The second generation are the sons and daughters of war veterans, or children born to parents who lived on contaminated land. Now there is a third generation, the grandchildren of the war and its victims.
This is a chain of events bitterly denied by the US government. Millions of litres of defoliants such as Agent Orange were dropped on Vietnam, but US government scientists claimed that these chemicals were harmless to humans and short-lived in the environment. US strategists argue that Agent Orange was a prototype smart weapon, a benign tactical herbicide that saved many hundreds of thousands of American lives by denying the North Vietnamese army the jungle cover that allowed it ruthlessly to strike and feint. New scientific research, however, confirms what the Vietnamese have been claiming for years. It also portrays the US government as one that has illicitly used weapons of mass destruction, stymied all independent efforts to assess the impact of their deployment, failed to acknowledge cold, hard evidence of maiming and slaughter, and pursued a policy of evasion and deception.
Isn't there a legal recourse people in Vietnam can use to get compensation and can the U.S. deny them by just denying it ever happened? I would have thought there could be a sort of "international court" punishing crimes against humanity like we did to Saddam Hussein, or is the "international court" an institution that only punish the losers during a war? The use of chemical weapon is clearly illegal and could be considered a crime against humanity. If so, can a country like the U.S. prevent from being prosecuted for it by denying it happened?