From the PDF:
The capital of Persia since 1789, Tehran has grown from a dusty backwater to a teeming metropolis of 800,000. In the last decade alone, Tehran has added 300,000 residents, many
displaced by the earthquakes, monster attacks, and other consequences of the Serpentfall.
And some of these new residents are here to play the secret game that Britain and Russia have played here much to the distaste of Persians of all stripes since the 19th century. But now the game is in new innings; played with a savage intensity here because Persia is almost the only court left for it. The Serpent Curtain lies across Europe, an impenetrable barrier. Turkey is surrounded by Soviet clients and conquests and by suspicious Soviet guards. Central Asia
and China are remote, plagued by warlords and bitter cold. But Persia borders Soviet territory directly, a border that moved much closer to Tehran after the Soviets annexed Persian Azerbaijan in 1946.
Less than 200 miles from the expanded Azerbaijan Soviet Socialist Republic, Tehran has become a veritable nest of spies. It draws those who would try to smuggle agents into the Soviet empire, and information out and it draws those who would move the Soviet border yet again, all the way out to the Persian Gulf and the doorstep of India.