Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother, in Islam, we would like to thank you for the very interesting question you posed and the great confidence you place in us, and we implore Allah Almighty to help us serve His cause and render our work for His Sake.
In his answer to the question, the late Sheikh Sayyed Ad-Darsh, former Chairman of the UK Shari`ah Council, states:
"The reason why there are strong actions against things like murder and adultery is because these are crimes against society. But you cannot expect Islam to be a religion that carries a big stick for everything. There has to be an area for the moral and spiritual upbringing of the person in these circumstances, to let him or her become familiar with things which are prohibited, and to develop moral perception.
Smoking in the way we know it was not a common practice at the time of the Prophet (peace and blessings be upon him). It came into fore in the last two centuries or so. So it is a new development for the Muslim community and it took the Muslim scholars great deal of time and effort to consider the harmful effects of smoking, until they came to the conclusion that it is Haram (prohibited). Once again, abstention from smoking is left to the moral sense of the person.
As for drinking alcohol, there is a specific Hadd for that. In the early days of Islam, people who had stopped drinking prohibited others and those who committed the offence were lashed 40 times. They use to flail the drinker with anything that came to hand - a piece of cloth, a shoe, a stick - just to let the person feel that he or she had indulged in something prohibited. Later on when there was a complaint that people were returning to the old ways of drinking, `Umar (may Allah be pleased with him) consulted the Muslims around, and `Ali (may Allah be pleased with him) said: "I think that drinking will make a person lose his mind and consequently start abusing others, uttering false accusations against them. So I think he deserves the same punishment for a person who falsely accuses other persons (Qadhif) that is 80 lashes." Henceforth, that became the standard of punishment for drinkers to stop them from falling into that."
Allah Almighty knows best.