belligerence
Aggressive behavior that shows someone is eager to fight.
Belligerence is aggressive hostility or eagerness to fight and argue. Someone showing belligerence is spoiling for a conflict, acting hostile and confrontational even when it's unnecessary, turning minor situations into battles.
You might see belligerence on a playground when one student responds to a simple “excuse me” by shoving and yelling, turning a minor bump into a fight. In history class, you learn about nations that displayed belligerence by threatening war over small disputes instead of trying diplomacy first.
A belligerent person or nation is one that's combative and hostile. During World War II, countries actually fighting were called belligerent nations, different from neutral ones staying out of the conflict.
Belligerence differs from simply standing up for yourself or having strong opinions. It's the unnecessary aggression, the looking for trouble, the hostile tone that turns disagreements into battles. When a student responds to every suggestion with belligerence, classmates stop wanting to work with them. When someone speaks with belligerence, their words come out harsh and combative, making others defensive even before the conversation really starts.