In late 1917, Second Lieutenant Nicol was awarded the Military Cross for bravery, after he led a party against an enemy counter-attack in a captured village. The citation, in the London Gazette, reported that in fierce hand-to-hand fighting, Nicol accounted for "six of the enemy himself".
Not one to blow his trumpet, the New Zealander told his parents after the investiture by King George V that "I've been up to the Palace to meet George, and he shook my dook".
Nicol, assigned the rank of temporary captain, had a solid reputation as a capable officer, handy with the Lewis gun and Stokes mortar and a skilled bomb instructor. It made him a perfect candidate, with 23 other New Zealanders, for special service with the British Army.
With volunteers from Australia, Canada and South Africa, the small band of brothers - the War Office had in mind a secret force of 100 officers and 200 NCOs - had a mission to block the Bolsheviks from the Caucasus.
It was a perilous and risky initiative - the NZ Rifle Brigade History notes the men were told when they assembled that few could hope to come through alive.
After two weeks being billeted in the Tower of London, where the soldiers were kitted out with fur-lined coats, caps and gloves, the unit learned the expedition would be known as Dunsterforce after Major-General Lionel Dunsterville, an Indian Army officer. The arrival of two Tsarist officers gave the Commonwealth force a clue to its destination, which was confirmed as the unit set out from Waterloo Station on January 29, 1918.
After crossing Europe as far as Italy, the soldiers boarded a ship for the Suez Canal and round to Basra before heading up the River Tigris to Baghdad in what was then Mesopotamia. The task set for Dunsterforce was ambitious: to blunt Turkish and German expansion reaching the rich Baku oil fields on the Caspian Sea.
The strategy involved the small Allied unit persuading Georgian, Armenian and Assyrian forces to hold the line against the rampant Turkish armies.
In early August, Nicol and a small team led by an Australian, Captain Stanley Savige, were sent to provide rearguard protection for a column of 50,000 fleeing Armenian and Assyrian Christians. The refugees had already retreated hundreds of miles to escape their ruthless pursuers.
Savige recorded the terror in his diary: "Turkish troops and Kurdish irregulars were raiding the column, murdering the people and carrying off girls to their harems, together with whatever loot they could lay their hands on."
Near a village called Sain Kaleh, Savige and Nicol kept up a stream of fire from their Lewis machine guns while the demoralised refugees streamed towards safety.
Nicol bravely kept up covering fire for the soldiers trying to save pack animals carrying ammunition and other supplies. A Court of Inquiry after the incident found that he was shot during this action, and "fell to the ground motionless".
Sadly, news of his fate was not conveyed to his parents, who died thinking their 24-year-old son was "missing in action, believed killed".
Nicol's name is inscribed on the Commonwealth War Graves Tehran memorial.