'This Week' Transcript: The Battle Against ISIS

— -- UNIDENTIFIED MALE: Starting right now on ABC THIS WEEK, breaking news -- terror in Denmark. A suspect killed in a shootout overnight.

Was a cartoonist on al Qaeda's hit list the terror target?

ISIS threat -- as President Obama makes his case for war, Martha Raddatz is on the ground asking why this enemy is so hard to defeat.

Plus, Hawk Eye hello -- Vice President Biden in Iowa. What he's saying now that's turning heads.

And Jon Stewart's signoff -- why he's had such an impact and who will replace him.

From ABC News, THIS WEEK WITH GEORGE STEPHANOPOULOS begins now.

MARTHA RADDATZ, HOST: Good morning.

I'm Martha Raddatz in Amman, Jordan.

All week, the world has been focused on this region and the threat posed by the terror group, ISIS, a threat that has been called the greatest since 9/11.

We've been faced with several stark reminders of ISIS brutality this week, beginning with the death of American Kayla Mueller, who died while being held hostage by ISIS.

Then Friday, a brazen attack by the jihadist group on an Iraqi air base with U.S. marines inside.

And just this weekend, ISIS releasing another haunting videotape that we won't air, this one purporting to show captured Kurdish forces being paraded through the streets in cages.

Back home, the president now asking Congress to authorize more military action to defeat the group.

But why is this threat so hard to contain?

We've been reporting from around the region, from Iran, to borders of Iraq and Syria all week, searching for answers.

But first, we have breaking news on the terror front. A suspected gunman is dead in Copenhagen. Police say the man is the prime suspect behind two attacks that left two people dead and five police officers wounded.

Chief foreign correspondent, Terry Moran, is in Copenhagen with the very latest -- good morning Terry.

TERRY MORAN, ABC NEWS CORRESPONDENT: Good morning, Martha.

Today, it is Copenhagen's turn to reckon with the aftermath of terror.

We are here at the site of the first of the first of the attacks yesterday afternoon, right back there. You can see the bullet-riddled glass, the cafe where this began. Danish security had been on high alert. But this attack came without warning. Its apparent targets, however, were grimly familiar -- a cartoonist and a synagogue.

(BEGIN VIDEOTAPE)

MORAN (voice-over): For hours, this city was gripped by terror. It began here at around 4:00 Saturday afternoon at this Copenhagen cafe, the first target. A gunman opening fire, firing 40 rounds. Police on the scene firing back.

(on camera): Inside, a panel discussion on art, blasphemy and freedom of expression.

Listen as the horror unfolds.

UNIDENTIFIED FEMALE: Why do we do things but when we...

(SHOTS FIRED)

MORAN: The host, Lars Vilks, he's a Swedish cartoonist and he's on an al Qaeda hit list for drawing the Prophet Muhammad.

Vilks, whose bodyguards rushed him into the cafe's kitchen, survived. But a 55-year-old man attending the event was killed.

UNIDENTIFIED MALE: I mean I'm not sure how many shots but I'd say (INAUDIBLE) 20 or 30 shots (INAUDIBLE) and people panicked, of course, and ran to the doors. Other people were hiding in behind tables they had turned over.