One in eight soldiers has attacked someone after coming home from a combat deployment, research suggests.
Ministry of Defence-funded researchers surveyed 13,000 Army personnel and say they found a link between combat and trauma, and violent behaviour - often towards their partners.
Former head of the Army General Richard Dannatt warned a cultural change is needed within the forces.
The Ministry of Defence said it had measures to manage violence.
The study by Dr Deirdre MacManus, at The Kings Centre for Military Health Research, found an association between soldiers' experiences in Iraq and Afghanistan, and violent behaviour at home.
Soldiers involved in direct combat were twice as likely as others to admit having hit someone at the end of the tour, the research found.
A third of the victims were someone in the family - often a wife or girlfriend.
Dr MacManus said: "The association between performing a combat role and being exposed to combat, and subsequent violence on return from deployment, is about two fold.
"We also saw that soldiers who had seen more than one traumatic event were more likely to report being violent."
This month an ex-soldier was jailed for shooting dead his landlady, just months after he had returned from serving in Afghanistan with the Territorial Army.
Aaron Wilkinson, 24, killed 52-year-old Judith Garnett, at her farm in Leeds.
Wilkinson had been diagnosed with post-traumatic stress reaction by an Army doctor. It developed into post-traumatic stress disorder (PTSD), but was not monitored or treated.