Tajikistan's willingness to allow a division of Russian troops to guard it's borders comes largely from the growing use of cheap Afghan heroin by Tajiks. The estimated number of heroin addicts in Tadjikistan has grown five times since 1997, to about 35,000. It costs about $30 a day to support a full blown addiction and most of the addicts steal to support their craving. A dose of heroin costs about a dollar. A bottle of vodka costs a bit more. Although most of the heroin produced in Afghanistan is for export to Europe and North America, there is so much of it that some can be sold locally. This is giving the nations of Central Asia, as well as nearby Iran and Pakistan, a common cause.