Often times as parents we use the words discipline and punishment interchangeably. I'd prefer to think of the two like this:
Discipline is the guidelines and set of expectations you set forth for your young ones
Punishment is the consequences of non adherence to this set of guidelines
Simple? Sounds simple... it is simple yet ever so difficult. Far be it from me to tell you this is a simplistic look at parenting. I made so many mistakes as a parent, however... I learned heartbreaking lessons that I share with you all in hopes of tempering your desire to let things ride verses nipping them in the bud.
Children need to be told up front and with authority what is expected of them. They need to have a clear understanding of acceptable and unacceptable behaviors. To us it may seem ridiculous to have to tell them that all drugs are off limits. But they need to hear it from YOU. Not just the school, not just the TV from YOU. It is your job as a parent to inform your children of this dangerous situations that can ruin their lives or take them. Just as you explain to them what you expect from them in terms of household responsibilities, school work, etc... they need to know all of peripheral issues as well, drug, sex, honor, honesty...
Outlining your guidelines and rules is the first step. The second step is letting them know clearly the consequences to breaking the rules. I had no problem with setting the guidelines... I had problems with sticking to the punishment "plans". Apply consequences to your young ones is not mean... it does not make you a horrible parent although they will probably bring that to your attention rather quickly... you do them more harm by NOT applying the consequences. If they see you crumble or disagree with a level of punishment...you are in for the ride of your life. They won't forget and they will play you like a fiddle moving forward. Again, been there... done that. They need to be ready for the grown up world and the early they understand that there will always be rules to follow the better.
Drugs kill folks... this is not kindergarten stuff... once our young ones start playing with drugs and alcohol on any level they have hit the big leagues ready or not. They have crossed the line from childhood into a dangerous... very grown up world. Get them ready to understand that... let them know... hold your ground and take back your family.