He promised to continue the fight against infidel forces.

他答应继续对抗异教势力。

《柯林斯英汉双解大词典》

Thus resolved, they wrap their faces in scarves and seek to fight the infidel.

ECONOMIST: Somalia's Islamists

They were jihadists, driven by their clearly articulated faith to kill the infidel, not empathize with them.

CENTERFORSECURITYPOLICY: Monica Crowley, Mightier Pen 2012

" Again, no mention of the hostility towards the infidel West ingrained in "the traditions of Islam.

CENTERFORSECURITYPOLICY: Deciphering Obama in Cairo