Answer :

Oil. But also the fact that it's geographical location has a results in its importance in terms of navy routes which becomes even more significant in times of war. 

Answer:

oil supply

Explanation:

The most valuable asset came in the pre world war epoch when the British found a huge reserve of oil and formed the Anglo Persian Oil Company in year 1908- a time where the motors where changing from coal based into oil based.

The discovery made striking news since it was the first of its kind in the Middle East and a wave of scientific research and innovation in extracting and exploiting of oil was booming.

The presence of oil in commercial dimension meant also alliances for an era of wars to come into the region as efforts to seize the desired asset would tell us.

The oil came to change also the face of everyday life , and Persia or Iran became one of the first consequences of oil based industries: automobiles, powerful navies, and steams running on oil.