John Watson, 35, ambushed Pte James Dicks outside his ex-wife's home in Windsor because he believed they were in a relationship.
He then tied Pte Dicks up, bundled him into a car and stabbed him before he was stopped by police.
Judge Angela Morris said Watson was a "danger to the public" as she sentenced him at Reading Crown Court.
She said there were "two John Watsons" and that while one was "a devoted family man who served his country with honour", the other was "one of anger, jealousy and murderous intent".
The court had heard the two men became friends while stationed together at Combermere Barracks, near Windsor.
However, their friendship broke down after 28-year-old Pte Dicks was accused by Watson of starting a relationship with his former wife.
On 4 May last year Watson "hog-tied" his victim after lying in wait for him outside his ex-wife's house and forcing him into his car.
He then tried to kill the Household Cavalry trooper by wrapping cling film round his face and attacking him with a jab saw.
The assault was stopped when two police officers armed with Tasers arrived at the scene, but Pte Dicks was left with stab and slash wounds.
Judge Morris told Watson: "You are the one who tried to wrap his head in cling film when he fought back in the second car park in an effort to escape and ultimately you are the one who was continuing to attack when the police eventually arrived on the scene."
She said but for members of the public calling police, Mr Dicks would have been dead.
Watson had already been found guilty of one count of kidnap in relation to the attack, and pleaded guilty to one count of possession of an offensive weapon.
He was convicted by a jury of attempted murder on 19 January.
Watson was sentenced to 19 years for attempted murder, four years for kidnap and six months for possession of an offensive weapon to run concurrently.
He was told he will have to serve 16 years before he is eligible for parole.
A soldier who abducted and stabbed his love rival has been jailed for a minimum of 16 years.