There is no real difference between alcohol abuse and drug abuse. Both can destroy your body. Both encourage you to do stupid things. Both encourage you to lose your job and your friends and destroy your life.
Do you know why you see more damage done from drugs? Because of prohibition. Alcohol is cheap and easy to get. You can spend your life drunk just by panhandling, if that's your goal in life.
Thanks to prohibition, drugs are expensive. If you want to spend your life high, you're going to have to start stealing from people, prostituting yourself, working for drug dealers, etc.
There is no logically consistent way to justify your support for drug prohibition without also supporting alcohol prohibition. It is pure hypocrisy.
That's not completely true. Drugs like meth can turn a young person old much faster than simply aging or alcohol abuse. Even so, if we want to use that as a reason to go to war, we still need to justify the threshold that causes us to war on one and not the other.