Yeah it is fine as actually Jet works on the body of a soldier, as it result effective. And as there was a massive use of Amphetamines (to calm down/have no fear) in real wars, this is a perfect example why the use of Jet, as the representative of, should be used when on duty.
As well as heroin, which is almost impossible to get rid off from an addiction to it, there should be a voluntary attempt to leave drugs, without total success as a condition. So, as suggested, there might be a solution as the possibility of restrain to the use of any drug, and the consequences of its dependence.
Make it difficult to achieve, with a very low effectiveness but, why is actually hopeless to have a slight chance of get a cure? In my opinion, there is not a real reason why to not implement a probable cure, while almost worthless - there could be so many variants: highly expensive to craft, very long cool-down, low percentage of success, etc - but not impossible.