VHG
It comes down to natural resources. We're not doing this merely for altruistic purposes.
Immediately across the Caspian from Azerbaijan, is the former Soviet Central Asian republic of Turkmenistan, an area of 488,000 sq. miles, bigger than the whole of Texas, Arkansas, Louisiana and Oklahoma combined. It has enormous oil, gas, coal and other natural resources and significantly, directly adjoins Afghanistan to the south.
Uzbekistan, which covers an area of 172,000 sq. miles, roughly equivalent to the combined states of Maryland, Virginia, West Virginia, North Carolina, South Carolina, Georgia and Florida, has vast resources in oil, gas, coal, copper and gold as well as being a huge cotton producer. It too, has a frontier with Afghanistan to its south, as does Tajikistan. Tajikistan Tajikistan is over 55,000 sq. miles, an area slightly bigger than Illinois. It too has very rich deposits of oil, gas, coal, lead, zinc, uranium, radium and many other minerals.