Jason Ferguson, 18, originally from Glasgow, and John Ward, 19, of Fife, targeted the vulnerable youngsters, dubbing them “spastic” and “mongol” on a drunken night out.
Their two victims - a 16-year-old deaf boy with autism and his 18-year-old autistic friend - met the squaddies on a night out near their base in the Brecon Beacons in south Wales.
A court heard the “naive, trusting and innocent” pair believed the two squaddies based in a camp in their home village were being friendly.
But the vulnerable teenagers were led into a trap in a dark alley where they were beaten up for fun by the pair.
Prosecutor Sue Ferrier said: “What happened beggars belief. They were unlucky enough to cross the paths of these men who had been drinking all night and were heavily intoxicated.
“Their two victims were targeted. They were identified because of their particular vulnerabilities.
“They led sheltered lives. They were particularly naive. They did not appreciate they were being lined up with what was to follow - a brutal and sadistic attack.”
The soldiers were on a drunken night out when they saw the “vulnerable” pair walking home and began targeting them with verbal abuse and filming the insults on one of their phones. The court heard the soldiers then took one of their mobile phones to lead them into the alley.
The youngest boy was beaten and kicked unconscious by Ferguson as his terrified friend was held back by Ward.
Miss Ferrier described it as a “shocking and sustained beating” which left him in a coma for three days.
Then his older friend was punched, kicked and hit with a terracotta pot.
The soldiers burned their clothing in woodland before heading back to camp after the attack in July of last year.
Glasgow-born Ferguson, of Leyland, Lancashire, admitted two counts of wounding with intent to do grievous bodily harm.
Ward, of Oakley, Fife, admitted wounding with intent to do grievous bodily harm and unlawful wounding.
Ferguson was sentenced to eight years in a young offender institution and Ward for seven years at Merthyr Tydfil Crown Court.