Why can't I Call to Arms on my allies sometimes?

[StriderX]

I've been called to war a few times now where I want to call in my other allies to the same war like the AI does continuously but on my other 2 allies the button Call to Arms doesn't show up. Castille called me to war which I answered but now I've been chained jumped by like 8 other nations and I still can't call in my allies.

What gives? Castille was the aggressor when they called me to arms.. It seems like that is when it happens. I can't call my other allies in when they are the aggressor and call me.

 

[Serzis]

Only the war leaders can call allies into a war. Sometimes the status of war leader can shift, such as when a bigger country is called into a war, enabling it to call in successively bigger allies (e.g. altmark-->bavaria-->France). Normally however, a junior partcipant can't call in more allies. Castille is already a large country, making it unlikely that leadership should be transferred to you.

 

[StriderX]

Ah. That explains it.