Don't know much to say about calling for prostitution to be legalized, except that from my own eyes, the only real obstacle to it would be religion and morality(admittedly VERY abstract ideas that are hard to prove). I can see the Westerners adapting real easy to this, but... East Asia? Middle East?
Now when it comes to drugs...
People like to look at Netherlands and say "THEY SMOKE POT LIKE COMMON CIGARETTES AND THEY'RE STILL A DEVELOPED NATION!!" With all the drug related violence going on and on and on dragging the society down for decades and taking God knows how many lives, it's really easy to just look at one thing and hastily call it the one savior for all problems.
Deep down, I think all the problems in regards to drugs won't go away with legalizing it. No, not even if you give it time.
Worse yet, I can't even explain why I feel this way. Well, at least I'm no politician drafting laws for your country so spare me the flaming. lol
Oh, and this topic reminds me of this conversation a few cop characters had amongst themselves in The Wire in reference to the ongoing 'war against drugs'.
"Hell, you can't even call this shit a war."
"Why's that?"
"Wars end."