Two things that I think are important to remember are:
1) If you ban something people are addicted too, they WILL be angry and they may become irrational and/or violent in their withdrawal.
and
2) Just because you ban something doesn't make it dissappear. People will still grow and buy tobacco in the same way they do with pot. Pot is smoked as much or more than cigarettes are at my school. It's not that hard to get, and tobacco wouldn't be all that different. Add on the fact that very few countries will have banned tobacco, it would become very easy to smuggle it over borders. Just hop a plane to another country, go to a store, buy them and then come back.
Outright banning may actually cause more problems than tactful weening off of cigarettes.