“It is only when we contest (ISIS') presence online, deny the legitimacy of the message it sends to vulnerable young people and expose (ISIS) for the un-Islamic cult of violence it really is ... that (ISIS) will truly be defeated,” Allen said.

Washington needs a holistic counterterrorism strategy that ensures its Arab allies do not use U.S. assistance to perpetuate terrorism and that supports those in Arab societies best able to combat radicalization.

The raids involving 800 federal and state police officers — the largest in the country's history — came in response to intelligence that an Islamic State group leader in the Middle East was calling on Australian supporters to kill, Prime Minister Tony Abbott said. Abbott was asked about reports that the detainees were planning to behead a random person in Sydney.

Egypt’s tourism industry, battered by three years of political upheaval, violence and street protests, could fully recover by the end of next year if regional turmoil does not spread to the Arab world’s biggest country, the tourism minister said. 

U.S. Secretary of State John Kerry arrived Saturday in Cairo on the latest leg of a regional tour to forge a coalition against Islamic State militants in Iraq and Syria. Kerry is scheduled to meet Egyptian President Abdel Fattah al-Sisi and Arab League chief Nabil al-Arabi. 

Mr. Obama is acting as polls show rapidly shifting public opinion, with a large majority of Americans now favoring military action against ISIS in Iraq and Syria, even as they express deep misgivings about the president’s leadership, Mr. Obama is also facing difficult crosscurrents on Capitol Hill, where Republican lawmakers, initially reluctant to demand congressional authorization of military action, have begun agitating for a vote...

The proliferation of social media has brought extremist ideologues world-wide into closer and more personal contact with potential recruits than antiterror officials ever dreamed possible, but it also has handed Western investigators powerful new tools for tracking potential threats.