[dragonwriter]

> Apologies for out-pedanting you, but I believe it is still called the past tense.

No. In "If we were in similar conditions again, we wouldn't do the same thing", the condition clause ("If we were in similar conditions again") uses the past tense, the main clause ("we wouldn't do the same thing") uses the conditional mood, which is marked (in this case) by the use of the modal verb "would".

In the sentence "We wouldn't do it again" where the condition is implicit, there is no use of the past tense, only the conditional mood.