co-belligerent

[Nukkxx]

Hi,
I'm not sure to understand exactly the concept of co-belligerent.
Here's from wiki:

Co-belligerence
If a country is not marked as a co-belligerent:

That country can't call its allies to arms in that war (but its subjects are called as normal). Beware that the Holy Roman Emperor defending the empire is always a co-belligerent.
Taking that country's provinces in a peace incurs Aggressive expansion impact.png +50% aggressive expansion and costs War score.png +100% warscore.
If a country is marked as a co-belligerent:

That country can call on its own allies to fight as well
If that country has a guarantor, it is called also
Taking that country's provinces will cost the same as the war leader's provinces

What does it mean "If a country is not marked as a co-belligerent" ? Is it when the box is unchecked or when there is no green checkmark ?

For each possible co-belligerent there are two things: the green check mark and the box that i can tick or not. What does it means if I tick the box ? if i don't ? Why is it the attacker who decides who are co-belligerent ? This isn't very clear to me.
thanks.

[Rensi]

If the box is checked, the country is a co-belligerent. If it isn't, it's not.
If there is a green tick, it means that the said country will join the war as an ally. If it shows a red cross, they will refuse the call to arms.

If you make an ally co-belligerent, it makes them a direct target of the war, rather than just an ally. That way, you can take land from them with less penalties. However, it also means that co-belligerent countries can also ask their own allies for help.

The attacker decides who is belligerent because it's the one who declares the war. The defender has no say in who is the primary target of the war. It's like while getting mugged on the street, you say "I'm not the one you are mugging, it's my friend over there." HRE members are the only exception.

[Nukkxx]

OK thanks for these clarifications. But why is it me, the one who declares war, who decides if my target's allies are co-belligerent ? Does it make sense ? Is it equivalent for me to declare them co-blligerent or declare war to them directly ?

[Nukkxx]

Well, in fact I think i do get it now :-) And it;s a rather good system !