I'll give the answer then.
The situation at that time was that Germany was winning on all fronts. They had recently captured Crete, made big progress in Northern Africa, Made huge progress in Russia and it was not unthinkable at that time that Germany could take Moscow and -more importantly- the Causasus Mountains (just north of Persia). If Persia would ally with the Allies it painted a target on its belly for German occupation.
On the other hand the British controlled Iraq and had just captured Syria and of course controlled India, meaning strong British forces to their East and West. And Russia, although beaten up by the Germans, still was a power far stronger than Persia, was seen making movements along the Persian borders. It was all to clear that Russia and Britain would invade, so allying with -still far away- Germany would be painting a target on its belly for British / Russian occupation.
So Persia had really no choice but to not side at all, but since Russian / British invasion was inevitable, it chose to put up only a token resistance, reducing the chances of brutal occupation and succeeding to keep the power in its own hands (Reza Shah abdicated in favour of his son who, educated in Europe and had pro-Western views, set up a government pledged to support the Allies).
This way Persia had an easy occupation time, without being a traitor to anyone and could count on Allied forces for defence and if Germany would break through, they could still claim they were invaded by the Allies and welcome the Germans as liberators - again preventing a cruel (German) oppression. Had it openly sided with the Allies, and Germany would have broken through, German revenge was feared.
I'm giving the next question to Serutan FF or Privatehudson, as they all got parts of the answer and I can't really appoint someone who was closest to the answer. First 1 of them to post a question gets it.
The situation at that time was that Germany was winning on all fronts. They had recently captured Crete, made big progress in Northern Africa, Made huge progress in Russia and it was not unthinkable at that time that Germany could take Moscow and -more importantly- the Causasus Mountains (just north of Persia). If Persia would ally with the Allies it painted a target on its belly for German occupation.
On the other hand the British controlled Iraq and had just captured Syria and of course controlled India, meaning strong British forces to their East and West. And Russia, although beaten up by the Germans, still was a power far stronger than Persia, was seen making movements along the Persian borders. It was all to clear that Russia and Britain would invade, so allying with -still far away- Germany would be painting a target on its belly for British / Russian occupation.
So Persia had really no choice but to not side at all, but since Russian / British invasion was inevitable, it chose to put up only a token resistance, reducing the chances of brutal occupation and succeeding to keep the power in its own hands (Reza Shah abdicated in favour of his son who, educated in Europe and had pro-Western views, set up a government pledged to support the Allies).
This way Persia had an easy occupation time, without being a traitor to anyone and could count on Allied forces for defence and if Germany would break through, they could still claim they were invaded by the Allies and welcome the Germans as liberators - again preventing a cruel (German) oppression. Had it openly sided with the Allies, and Germany would have broken through, German revenge was feared.
I'm giving the next question to Serutan FF or Privatehudson, as they all got parts of the answer and I can't really appoint someone who was closest to the answer. First 1 of them to post a question gets it.