Tacitus said about the Romans at Carthage, "You have made a desert and
call it peace". Did he continue to develop this thought? Did other
Roman historians counter this thought? Have other Roman or Greek
authors commented on the role of war in spreading freedom to other
countries-either pro or con?

Remember they spread salt on Carthage

- their equivalent of 'glassing' the place

Perhaps 'Freedom is in the eye of the bestowers'

Your quotation is incorrectly attributed. It is from Tacitus, but is
from his life of Agricola (Agricola was Tacitus's father-in-law). The
quotation comes at the end of chapter 30 of the 'Agricola'.
The context is NOT Carthage. The scene is at Mons Graupius, (Graupius
Mountain) in Britain. A bunch of Britons, led by Calgacus (also
spelled as Galgacus) are facing the Roman invaders. In Chapter 30, 
Calgacus gives a hortatory speech before the battle. It includes the
words, 'They (the Romans) make a desert and call it peace.'
So, it wasn't  Carthage. And it is Tacitus imagining what an early
Briton would say when facing a Roman invasion. He wasn't there, so the
speech must have been invented by Tacitus.

Here is a link to an undistinguished translation:
http://www.fordham.edu/halsall/ancient/tacitus-agricola.html

Incidentally, I've just looked in my Latin copy of the book ('De Vita
Agricolae') and the Latin phrase is:
' atque ubi solitudinem faciunt pacem appellant'
'And where  they make a desert and call it peace'.