Tobacco, whether smoked or chewed, is now widely considered an addictive and dangerous drug. However as its impact on consciousness is slight most Buddhists do not consider smoking to be breaking the fifth Precept. In Burma and Japan smoking by monks is common as it is in Thailand amongst monks of the Mahanikaya sect. In Sri Lanka and amongst Tibetans and Chinese smoking by monks is looked down upon and they usually refrain from it. So from the Buddhist perspective smoking may well be unwise but is does not have a moral dimension.