Canids are capable of experiencing multiple feelings simultaneously. In particular, canids can be both submissive and aggressive at the same time.
Some canids initially react to threats by behaving submissively. They display appropriate signs of active submission by offering appeasement signals or otherwise acquiescing to the threatening postures of the other canid or human.
Some canids might offer signs of passive submission, by rolling onto their backs and exposing their vulnerable belly or inguinal area.
Sometimes, the threatening canid or human ignores or does not accept the offered signs of submission. The aggressor may escalate his threats instead. The submissive canid’s options become limited to flight, immobility (freeze) or fight. If flight is not possible, the canid is likely to resort to the survival mode – bite the human or fight the other canid. The submissive canid resorts to aggression, aptly called submissive aggressive behavior.