Well... except for declaring war. That's not aggressive at all... ^_^
There's the concept of casus belli which states that even if X was the first who officially declared war, if Y gave a reason to spark aggression, then X is not considered the aggressor.
Exactly. Casus Belli. Repeated and unapologetic treaty violations, public vulgar insults, attempt to start a war anyways (the infamous blood bribe), and attempts to sabotage alliances.
And, "declaring war" is not a universally identical concept. The war we declared precluded the possibility of ever invading Kabrinskia, unless Kabrinskia invaded us first.
