The movement known as Jangalis (literally those from the jungle meaning guerrillas of the jungle) were first trained by the Austrians to foment trouble for the Allies in WW I before turning towards communism which caused the British to tolerate/arm the Persian Cossacks and send forces to the Caspian.  The Brits having occupied northern Iranian territories In their fight against Bolsheviks effectively ragged Iran into the Russian civil war.  The excerpt below from General Dunsterville's diary records his first steps in that process. The General, who had just been promoted, had landed in Basra where he was briefed by his fellow officers including Sir Percy Cox:

January 19th [1918]
   Owing to the secrecy of my arrangements, I am called the Commander of the "Hush, Hush Army".  I blossomed into a Major-General yesterday - as it was obviously foreseen Daisie had made the holes for the new resplendent stars. After fixing up all plans to start. I get a wire to say that Enzeli, my destination on the Caspian Sea has been seized by some horrid fellows called Jangalis (a very suggestive name) who are intensely anti-British and are in the pay of Germans. It will have to be plot and counter-plot. 

   These long journeys are full of dramatic change. I am just waiting to jump off into darkness and eternity for a space, with a fair hope of emerging on the far side, and here I have a pantomime with string band and as I stand on the verandah at night, the romantic Tigris flowing as it has flowed for many thousand years, and the moon-light on the water, and everything good the world holds except Daisie to share the beauty and romance of it - but women have no romance!