From a post to Baen's Bar Honorverse dated June 19, 2008:

The League vs the Star Empire of Manticore: Who declares war on who?

    Who declares war on who?

   

    This is one of those "I could tell you the answer, but then I'd have to kill you" questions. I think, however, you can take it as a given that the Star Empire definitely doesn't want to declare war on the Solarian League, and that the Solarian League would find it extraordinarily difficult to legally declare war on anyone.