Defoliant spray run, part of Operation Ranch Hand,
during the Vietnam War by UC-123B Provider aircraft.
Source: USAF / Wikipedia

Mix equal parts of the broad-leaf herbicides 2,4,5-Trichlorophenoxyacetic acid (2,4,5-T) and 2,4-Dichlorophenoxyacetic acid (2,4-D) and you’ve got yourself a batch of what’s commonly known as Agent Orange, the defoliant made famous during the Vietnam War. Herbicidal warfare was used first in Malaysia in the 1950s against communist insurgents. Based on this earlier implementation, with the approval of President Ngo Dinh Diem of South Vietnam, the United States began using it in 1961 against communist insurgents there.

The use of various chemicals in warfare was first declared as outside the boundaries of acceptable conduct in 1925 under the Gas Protocol, then under the Environmental Modification Convention (ENMOD) of 1978,  and again on April 29, 1993 under the Chemical Weapons Convention (CWC). The Organisation for the Prohibition of Chemical Weapons (OPCW) was established to ensure that the closure of chemical agent production facilities is monitored, and that stockpiles are destroyed.

Chemical weapons are relatively cheap, easy to mix (if you don’t count the potential hazardous effects on those doing the mixing), quick and lethal to use. Still, many states have been compliant with the CWC. Some, of course, have not. Or at least, not until it suited them.

Syrian chemical weapons
Source: Military.com

Even when the chemicals are no longer in use, though, they tend to leave a long legacy in the form of damage to the victims who survived any initial attacks, as well as those who come into contact with the chemicals at any stage of their implementation and (sometimes) their disposal.

In the case of Agent Orange, U.S. war veterans of the era still suffering the effects of exposure. Among Vietnamese victims, chemical warfare hasn’t abated, with effects still evident in the grandchildren of those exposed.

Much of the environment that was sprayed in Vietnam four decades ago still hasn’t recovered. Many areas remain barren, or much reduced in biodiversity and fertility. Reforestation projects are underway to redress some of the damage done, but invasive weeds, the loss of tree seeds to renew the original habitat, as well as the devastation of regional fauna make the task a challenging one.

April 29: It’s the annual Day of Remembrance for All Victims of Chemical Warfare.