@trig I’m still going to have to disagree. I don’t think movement is done in discrete steps, ie one zone after another, but it’s done all at once (save screening forces). 8.2 states that “A player moves all units that are conducting combat,” you can’t be conducting combat until you are at war with a nation. You are either at war with a nation or you are not; there isnt a middle ground where you a pseudo at war (ie at the end of a combat move but not the beginning). You did say before that escorting is a combat move, and this is true, however in 83 there is no Italian line to escort.
Furthermore an Italian Navy can not combat move into 81, or 82 as no combat is taking place in that zone, those are non-combat moves.
Finally your example breaks down at 3) because according to 0.5 Sharing Zones:
(b) Major Powers that are not at war with each other may freely share sea zones and do not affect each other. There are instances when units that are at war might share a sea zone such as
- When naval units of Major Powers that are not at war suddenly come to war.
In these cases, units do not participate in combat until one power makes a new combat move during combat movement phase against the other units in that zone.
In your example after they move into SZ83, it is too late to declare war and conduct combat as, due to 0.5 they are allowed to share sea zones despite being at war.
As @Didier_de_Dax pointed out “The Attacking player must always announce his intention first”, saying im going to attack that fleet over there is a Declaration of War.