Originally Posted by horatio
ENT didn't change everything as it did not portray the Romulan War.
It's not like Romulus is around the corner, so Romulans and Humans couldn't make contact (resp. come so close to each other that the Romulans feel threatened) without warp drive. As the Federation is founded after the war, humans must have been out there for some years and met Tellarites and Andorians.
In short, ENT makes perfect sense if you don't focus just on a few Spock lines but on the entire picture which includes first contact with the other three founding members of the Federation, the slow development of trust between them and the Romulans attempets to undermine this trust.
Furthermore Spock's statement only makes sense if there was a temporary technological regress during the war (before and afterwards warp technology is used). If the war is bloody, if the Romulan threaten to conquer Earth you don't need warp vessels, simple impulse drive will suffice. And H-bombs are probably simpler to produce than antimatter bombs aka photon torpedoes.
ENT doesn't really even contradict that so much either. If we have a think about the number and style of ships they have.
As the war was fought with ships -
well, in five seasons of ENT Earth had only built two NX ships. They don't have hundreds of them to field in battle. That's not going to last very long in a war so probably it was also fought using older
Earth ships as well. Which may have been armed with more primitive weaponry.
Also Spock says nothing that proves those ships don't have Warp Drive at all. But a more primitive ship then may only have had a speed of Warp 2 etc. The Warp 5 engine wasn't in every ship. Also bear in mind Spock will be referring to primitive by the 23rd Century - he says 'by our standards today' aka 2266 - in the actual time of the war it may be those ships were contemporary.
Ones which could fit the description Spock used.
Although I'm not the biggest ENT fan, there's actually not a massive amount of contradiction between Spock's words (which as a summary are also hardly definitive of a complete war) and how ENT presented the Star Trek universe when it left it.