They are not going to hit a city of course but a piece of the military infrastructure should NATO forces get involved. (And the target will not be in one of the Baltic states, I am sure.)

I'm not so sure NATO membership matters as much as people think, at present it seems like a convenient excuse to not intervene.

If the US retaliated with a bomb on Russian soil, would the expectation not be full-out nuclear war? Would it be smart for the US to enter that because Russia bombed Latvia?

Attacking a NATO member in a significant manner would trigger nuclear war. That's the actual meaning of the alliance, the treaties make retaliation compulsory, if the action is a clear attack by a nation-state. Refusing to carry it out would immediately result in effective disbandment of the alliance, with massive effects on the economy of Europe and the US.

This logic doesn't really track... you think the US would directly invoke nuclear war for the sake of an agreement that includes baltic states because if it doesn't... it could hurt the economy? I have no doubt that "hurt the economy" would be preferred to "destroy parts of the country"

NATO doesn't have multiple tracks - a member is a member. The US and their allies understood very well what that meant when they accepted those new members. NATO is about retaliation after external (and generally accepted to mean Russian, in practice) attack, or it isn't at all.

This is not a case of Turkey whining about a few kurds blowing up a few police stations, this is the raison d'etre for the whole thing. Renouncing NATO duties would be the worst loss of dignity the US ever experienced, and would jeopardize its richest partner market, with uncalcolable losses.

How is it the US "invoking nuclear war" if Russia nukes a US ally first? No, Russia's the one starting that war if they do that. Yes, the US would retaliate.

Yes they will. Don't have a single doubt about that. If they don't then their treaties aren't worth more than toilet paper for Putin to use. Make no mistake, NATO will protect its member countries.

What makes you so confident? Treaties have been broken for lesser reasons throughout history. It seems unlikely a country would be willing to enter a nuclear conflict for an ally with a GDP 500 times smaller.

it does matter, that's why it's so hard to get in. One step across a NATO border and the Russians will have started WW3. Don't have any doubt about that.

I don't think we'd launch nukes over one step.

I think Russia could even get away with "peace keeping" a "Russian separatist group" in a Nato country like Latvia.

Which is what makes this war so strange. Russia could've easily stolen Donbas - and NO ONE in the world would've cared. They could've taken away one state at a time, and NO ONE would have cared. There was no reason to rush.

But if Russia nuked a NATO population center, or even just invaded to this degree a NATO country - that's MAD.

You don't really sound like you know what you are talking about.

Safe to assume we're all dogs here.