and when they do not go forth in Allah’s cause, Allah punishes them by dividing them into factions and making them taste one another’s violence.

The same applies to His words:

“We will surely make them taste the lesser punishment before the greater punishment, so that they may return.”

The lesser punishment includes what is inflicted at the hands of people, just as some of the punishment Allah threatened the polytheists with has been interpreted as the Battle of Badr.