Iraqi troops enter a town seized from ISIS militants in 2017.
AHMAD AL-RUBAYE/AFP via Getty Images
- The New Orleans attack suspect carried an ISIS flag and pledged fealty to the group, officials said.
- The group, best known for global mass killings in 2015-2017, has again been gathering strength.
- The group was damaged but not defeated by a US-led campaign.
Back in 2017, the ISIS militant group's reign of terror appeared to be coming to an end.
A US-led...