(V):
I remember some 12 years ago China was critized on human rights ground because they executed 67 drug dealers.  The attitude of the Chinese government was one of eradication through the highest applicable legal penalty.  It worked to some extent although China still has problems with drugs, like most other countries around the world.  Their tough approach would probably be acceptable to some people who see no other way out other than extermination.

In many countries drug-related offenses cause a huge drain in the economy.  In the US about 80% of the people in the corrections system were incarcerated due to drug-related offenses.  That means that about 4 million people are there due to drugs and the cost of incacerating them is huge.  It hasn't worked because drugs are still a big problem in the streets.  Here in Canada the situation is the same and drugs are everywhere.

The Netherlands legalized some of the "softer" drugs like marihuana and hashish.  It seems to have worked for them, but politically their approach would not be acceptable to other countries.

I think that it is a losing battle.  The only way it will end is when poverty is eliminated both at the source of the drugs where poor farmers plant drug crops to survive, and at the destination where demand is fuelled by poverty.  This has to be accompanied with legalization of some drugs, and stronger penalties for trafficking others.  Marihuana, hashish, and LSD are not as destructive as cocaine and the amphetamines.  I think that penalties for possession have to change depending on the drug.  We see some of this here in Canada where possession of small amounts of marihuana has become tolerated by the law.  It might not solve the marihuana problem, but it has certainly kept a lot of people out of jail and out of descending into a life of crime.