For which reason did persia attract foreign interest in the early 1900s

The discovery of petroleum in 1908 by the British was the main reason why there was renewed interest in Persia, in particular by the British Empire. Both the United Kingdom and Russia began fighting for control over the region (this was called "The Great Game"). The conflict ended with the Anglo-Russian Convention of 1907, which divided Persia into two spheres of influence.

The reason why persia attracted foreign interest in the early 1900s was :
Oil was discovered in persia
early 1900s was the era of early industrial revolution, which made oil as one of the hottest commodities in the world

Russia lost the Crimean War for many reasons, one being their geographic hindering from their neighboring Black Sea, which caused a diminished reaction and disabled their ability to attack.