‘This Week’ Transcript: Loretta Lynch

— -- THIS IS A RUSH TRANSCRIPT FOR "THIS WEEK" ON JULY 26, 2015.

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ANNOUNCER (voice-over): Starting right now on ABC's THIS WEEK -- breaking news. ISIS under fire. A U.S. ally opens up a major new front against the extremist army.

Is this a game-changer in the fight to take down ISIS?

And (INAUDIBLE) the new terror threat at home. America's top prosecutor taking on what might be our most serious moment since 9/11. Pierre Thomas is one-on-one with Attorney General Loretta Lynch.

Planned Parenthood uproar, the group's president here live to respond to those undercover videos. It's an ABC News exclusive.

Plus, Hillary's campaign on the brand new email firestorm.

And Trump's GOP lead gets even bigger. What he is saying now that has him surging in the polls.

From ABC News, THIS WEEK with George Stephanopoulos begins now.

GEORGE STEPHANOPOULOS, ABC HOST: Good morning, all of the news from the campaign trail coming up. Donald Trump and Hillary Clinton dominating the headlines this week.

But we begin with that brand new front in the fight against ISIS. Key American ally Turkey now joining the fight for the first time. ABC's Alex Marquardt brings us the latest from Beirut.

Good morning, Alex.

ALEX MARQUARDT, ABC NEWS CORRESPONDENT: Good morning, George.

Turkey has long been accused of not doing enough in this fight against ISIS, of standing by while fighters and weapons cross their long border into Syria. But now Turkey has suddenly and dramatically stepped up its role in a way that could have big consequences for both ISIS and itself.

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MARQUARDT (voice-over): For the first time, wave of airstrikes by Turkish jets pounding ISIS positions in northern Syria. And Turkey, a NATO ally, now also agreeing to let the U.S. use an air base in the south, to launch drones and fighter jets against ISIS, bringing American pilots far closer to their targets.

Turkey jumping into the ISIS fight just days after a suicide bombing in Southern Turkey blamed on ISIS that left over 30 dead.

COL. STEVE GANYARD, ABC NEWS CORRESPONDENT: This is probably more than the U.S. ever expected to gain, we were only asking for basing rights. But now we're getting basing rights and we're getting the Turkish air force contributing to the attacking of ISIS within Syria.

MARQUARDT (voice-over): Now, Turkey is hoping to push ISIS back from its 560-mile-long border with Syria. But they're also targeting the Kurds, long-time enemies who Turkey has now started bombing in Northern Iraq, a dicey situation for the U.S. because the forces Turkey is hitting are allied with fellow Kurds supported by the Pentagon and fighting against ISIS.

So, what the U.S. has gained in air support could potentially hurt on the ground.

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MARQUARDT: And more Turkish strikes are expected as the U.S. looks to ramp up its efforts from Turkey. But the big question is, is this the game-changer that U.S. officials are hoping for -- George.

STEPHANOPOULOS: OK, Alex, thanks. Let's bring that question to Admiral Jim Stavridis, former NATO commander, now the dean of the Fletcher School of Law and Diplomacy.

Admiral Stavridis, thank you for joining us.

Is this a game-changer?

ADM. JAMES STAVRIDIS, FORMER NATO COMMANDER: I would call it an extremely significant move; we'll know in about a year whether it was the game-changer. But the key is going to be whether Turkey will put boots on the ground to cross that border.