Why will this never end?

With the Law of supply and demand, the wars in Juarez will never end. Some people say that "This will end eventually because every thing else does" but this won't. Because the only way this to stop supply is to stop demand. So when drugs in America are no longer in demand the need for demand will stop. So when these large drug cartels actually make upwards in to the Billions they will always have the resources to acquire weapons and man power to fuel their surge to get to the top of the food chain. But the thing is that there is no one man at the top of the food chain in Mexico there's multiple big men and families that have the ability to acquire men and weapons. But after saying that I just thought about it and i also think that another way for this conflict to end is have one drug lord take over the whole entire area because if there aren't any others you could have less violence than what we have right now. but of course since we are also in the war against drugs we will eventually weaken that one subject and there will be others waiting to take over. So I guess this is just the start of a long cycle that will go on forever and ever.