He said the work the Army "did post-9/11 was completely different" than before the attacks, adding "it changed the Army forever".
And Mr Goater said troops had "a different view" of the attacks than civilians.
Watch: 'Which movie is this?' – How British veteran remembers 9/11 reaction.
"Once we got over the initial shock of the scale of the attack, thoughts very quickly turned to, 'This is going to kick off somewhere, we're going to be going somewhere," he said.
He also said the attack on 11 September 2001, was a generation's "Kennedy moment".
"I think people that were alive and actually witnessed the attacks know where they were at that exact point and it's something you will never forget about."