First of all, you should specify which drugs you mean. In your question, you mention drugs in general, but in your explanation you mention marijuana. I think that many more people would be willing to legalize marijuana than, say, meth or cocaine.
Myself, I'm not a true believer in legalization of marijuana, but I do not think it would be a bad thing. First of all, you say that we need to keep "things under control." I wonder if we really are keeping things under control. We spend a lot of money on the "War on Drugs" and yet it does not seem difficult for people to get marijuana. So what good is all that money doing?
On the other side of the equation, what harm would we see if marijuana were legalized? It is not clear to me that many more people would start to use it. I do not think there are a lot of people saying "I'd really like to smoke marijuana if only it were legal." So I'm not sure what the harm would be. In fact, it might be that people would be less likely to use it because the "thrill" factor of doing something illegal would be gone.
Finally, we could make a lot of money for the government by legalizing it. If it were regulated and taxed, it might help with our government financing problems.
Overall, then, I don't feel strongly about this, but I think that there are good arguments for legalizing marijuana.