You are correct Perish is a verb. Also, it is a intransitive verb, which means it has no direct object. It will lead is in future tense. - It will happen in the future. Lead is a verb. It will expresses probability that that nation will perish.

Can we say: it will BRING the nation to ruin/destruction?

Don't worry Craig. Grammar is something silly that non-native speakers use to check their own writing or speaking, and that non-native teachers use to challenge their students. For native speakers, it's natural to detect mistakes and produce good sentences just by asking yourself what I will naturally say.

Hmm you got some lovely answers detailing what intransitive verbs can do (which I know nothing at all about). But I'd more commonly hear, "it will lead the nation to ruin" or "it will cause the nation to perish". That's the thing about me, I'm great at regurgitating information but sometimes I have no idea why it's grammatically preferable. Academically speaking. It makes me doubt my right to call myself a tutor or a teacher.

在我看来，“it will lead the nation to destruction"是比较正常的