Flag of IRAN
During the age of colonial empires, they sat at the Nexus between the two great Empires of Europe. The leader from the West, the United Kingdom adopted Iran and the leader from the East, Russia adopted Tajikistan.
During the Cold War they were initially polarized to opposite ends. Iran became a puppet for the United States while Tajikistan became a puppet of the Soviet Union. However the deep connection to Islam would allow them their space between these two technologically superior 'alien nations.'
Flag of TAJIKISTAN
Near the end of the Cold War, Iran would thaw itself out first. Resisting both the USSR and USA choosing the path of their native version of Islam.
Subsequently a tragic river of blood was spilled in the 1980 Iranian-Iraq war as Islamic Brother fought Islamic Brother. Likewise after the fall of the Soviet Union, Tajikistan entered a deadly phase of Civil War with Islam on Islam warfare.
Today both nations are relatively stable but yet resentful of the past history with the USA for Iran and the USSR for Tajikistan.
Iran and Tajikistan are Islamic Nations in between Eastern 'World of Middle Earth' (China) and Mediterranean World of Rome. They worship God in a similar format (Islam) and speak in a similar tone, Persian.