When the bombers are women - and children, which I predict we'll see more of - the terrorists get more bang for their buck, because there's more media attention.

The terrorists provide an outlet where with just one action, a raped woman can go from being a source of dishonour to her family to being a source of pride in a culture of martyrdom.

The best predictor of a woman's involvement in terrorism, whether it's a secular or religious group, is a relationship with a terrorist: her father, brother, husband or even her son. Terrorism becomes a bit of a family business.

I did a study of soldiers returning from Iraq, and their levels of PTSD were much higher if they had had to shoot a woman or child, even if they knew the person was a suicide bomber.

A lot of movements use women's involvement to shame men when recruitment is sagging.

With a civilian target, female bombers tend to be more successful and cause more damage.

Women are secretaries of state and prime ministers - but people still don't expect women to be involved in violence.