Neither non-lethal violence nor psychochemical weapons are new concepts. History provides examples of attempts to use these both to limit the scope of war and to turn mind-altering compounds into weapons. One of these substances has been marijuana. Although previous efforts to find its military applications failed, the idea persists - as indicated by a US patent granted in 2017. As "weaponized cannabis" may again attract the interest of government agencies, the consequences of its potential deployment call for a debate. In an attempt to encourage such a discussion, in the context of the ongoing decriminalization/legalization of marijuana in some countries and US states, the article raises ethical issues pertaining to weaponized cannabinoids. It argues against the militarization of the drug, on the basis that such a development would constitute an ultimate instrumentalization of marijuana and result in a dangerous destabilizing reconstruction of its meaning along the lines of state coercion.