Persia was divided into spheres of influence in

1907 is the answer

In 1907 the Anglo-Russian Convention was signed. This convention solidified boundaries and identified the control of Persia, and Tibet and also delineated spheres of influence in Persia.

It basically was responsible for designating which parts of Persia should be to Russia or British possession. This agreement did not eliminate competition between the two countries but it helped with cooperation and reduced conflicts.

power       the answer is a

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