By Carol E. Lee, Colleen McCain Nelson and Danny Yadron 

WASHINGTON--President Barack Obama pledged unwavering U.S. support for European nations facing a new wave of terrorism threats, including France and Belgium as they carried out raids that led to the arrest of some two dozen people suspected of terrorism links.

Mr. Obama, speaking at the White House on Friday during a news conference with British Prime Minister David Cameron, said the two leaders discussed a range of security issues, including the fight against Islamic State militants in Iraq and Syria and negotiations with Iran over its nuclear program.

But the terrorism threats that have gripped Europe since the attacks in Paris last week dominated their meetings, Mr. Obama said.

"This phenomenon of violent extremism--the ideology, the networks, the capacity to recruit young people--this has metastasized, and it is widespread," Mr. Obama said. "This is a problem that causes great heartache and tragedy and destruction, but it is one that ultimately we're going to defeat."

Mr. Cameron said the world is facing a "poisonous, radical, death cult" ideology and vowed to confront terrorism "wherever it appears." The British prime minister echoed Mr. Obama's resolve, saying, "We know what we're up against, and we know how we will win."

Mr. Cameron said the world is sickened by the terrorism, adding that the real enemy is the poisonous narrative that is perverting Islam.

Police in Belgium on Thursday arrested 13 people thought to have been on the verge of carrying out attacks on police officers, authorities said Friday. French police also arrested two people with links to the plot, Belgian authorities said.

Mr. Obama cited alienated Muslim populations as Europe's greatest danger.

Mr. Cameron said recent events present an opportunity for European countries to make sure their systems for tackling the problem are fortified. He highlighted the importance of updating legislation to address evolving threats and the necessity of building strong and integrated societies.

Amid increased concerns of terrorist attacks, Mr. Obama said it is problematic that new communications software--made by major U.S. technology companies--can prevent police from reading suspects' messages even if they have a court order.

Those comments marked the first public foray by the president into a public debate about whether Silicon Valley should be able to make gadgets that go to great lengths to protect users' privacy, even if it means locking out police as well.

"When we have the ability to track that, in a way that is legal, conforms with due process, rule of law and oversight, then that's a capability we have to preserve," Mr. Obama said.

Last year, Apple Inc. provoked a public fight with the Federal Bureau of Investigation when it said its new iPhone software would encrypt all data on the phone and could only be unlocked by a customer's passcode, which Apple doesn't know. In the fall, Facebook Inc.'s WhatsApp said it would start using a new encryption that not even the company could unscramble. Other venture-backed startups are creating similar apps that have become popular with privacy hawks.

"If we find evidence of a terrorist plot...and despite having a phone number, despite having a social media address or email address we can't penetrate that, that's a problem," Mr. Obama said.

The Clinton administration fought and lost a similar battle with technology companies during the so-called crypto wars in the 1990s.

The president described U.S. tech firms as "patriots" and said that technical issues would have to be sorted out. But it isn't clear whether Silicon Valley executives are on board.

Write to Carol E. Lee at carol.lee@wsj.com, Colleen McCain Nelson at colleen.nelson@wsj.com and Danny Yadron at danny.yadron@wsj.com

Access Investor Kit for Apple, Inc.

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=US0378331005

Subscribe to WSJ: http://online.wsj.com?mod=djnwires

Apple (NASDAQ:AAPL)
Historical Stock Chart
From Mar 2024 to Apr 2024 Click Here for more Apple Charts.
Apple (NASDAQ:AAPL)
Historical Stock Chart
From Apr 2023 to Apr 2024 Click Here for more Apple Charts.