The terrorist attacks of Sept. 11, 2001 have changed the world in ways both “subtle and profound,” said DePaul University history professor Thomas Mockaitis. (WTTW News)

Saturday marks the 20th anniversary of the deadliest terrorist attack on U.S. soil. Local experts join us to discuss what we’ve learned about terrorist threats since then — and how safe we are today.

This file image made from video posted on a militant website April 29, 2019, purports to show the leader of the Islamic State group, Abu Bakr al-Baghdadi, being interviewed by his group’s Al-Furqan media outlet. (Al-Furqan media via AP, File)

Eliminating the Islamic State group’s elusive leader gives President Donald Trump a new argument for leaving Syria, but the U.S. military campaign against the extremists is far from finished.

Vice President Mike Pence: “The space environment is fundamentally changed in the last generation.”

The president proposes a new branch of the military for space defense. Local experts weigh in on Space Force.