I believe the U.S. Government when they allege that Syria intentionally used chemical warfare on their own people. However, was the use of Agent Orange/Dioxin chemical warfare in Vietnam and other places chemical warfare also? There are some distinct differences.
First of all, the Agent Orange/Dioxin chemical manufacturers knew that the poison dioxin was a byproduct of the manufacture of Agent Orange but they did not tell the US Government about the poison for many years. The manufacturers were more interested in monetary gain. This disclosure is in legal documents obtained in the discovery process.
Second, the chemical manufacturers held a secret meeting about the dioxin problem and decided to keep the deadly knowledge secret.
Third, I highly respect the White House for disclosing the true on Syria's chemical warfare. However, there is a shocking irony on Agent Orange because the US Government has only partially paid for the damage done from Agent Orange especially on birth defects. This includes the storage and use of Agent Orange/Dioxin in Camp Carroll, South Korea