Before the start of business, Just Security provides a curated summary of up-to-the-minute developments at home and abroad. Here’s today’s news.

ORLANDO NIGHTCLUB ATTACK

The attack on the Pulse gay nightclub in Orlando, Florida, in the early hours of Sunday morning has left 50 dead and 53 injured in what is “the worst mass shooting in United States history.” The man enforcement officials say is responsible, Omar Mateen – who was shot by police at about 5am Sunday – reportedly rang 911 before carrying out the attack to proclaim allegiance to Islamic State. [New York Times’ Lizette Alvarez and Richard Pérez-Peña; Wall Street Journal’s Valerie Bauerlein et al; Washington Post’s Hayley Tsukayama et al]

President Obama called the attack “an act of terror and hate” on Sunday, confirming that the FBI is investigating the shooting as an act of terror. However, he cautioned, the gunman’s motives are not currently clear. [The Hill’s Jordan Fabian]

“Islamist-fueled terrorism, homophobia, the easy availability of weapons of war”: in this situation, where there are so many possible factors, “there is a temptation to draw too many lessons, or draw them too soon,” cautions the Washington Post editorial board. But, it says, the attack was “not a bolt from the blue,” and there are lessons “staring us in the face.”

“Can we finally drop the illusion that the jihadist fires that burn in the Middle East don’t pose an urgent and deadly threat to the American homeland?” writes the Wall Street Journal editorial board, which draws the conclusion that the FBI is “right to use “sting” operations against Americans who show jihadist leanings on social media or with friends.”

Islamic State was quick to claim responsibility for the attack, releasing a statement on Sunday which referred to Mateen as “an Islamic State fighter.” [The Hill’s Jessie Hellmann]  The terrorist organization’s supporters utilized social media to express approbation for the massacre, calling for similar attacks across the globe. [Wall Street Journal’s Maria Abi-Habib]

Was Omar Mateen directed by ISIS? Asks Jason Burke in the Guardian. The emerging scenario is that he was “inspired, but not directed,” by the terrorists, reports Burke, drawing parallels with the San Bernardino shooting in California late last year, where the attackers pledged loyalty to Islamic State on social media before carrying out the attack. Islamic state subsequently accepted that pledge.

Mateen had been interviewed twice by the FBI in 2013 after co-workers reported that he’d suggested he had terrorist links. The FBI closed the investigation, having been unable to verify any links. Then, in 2014, the FBI discovered a potential tie between Mateen and Moner Mohammad Abusalha, who became the first American suicide bomber in Syria, for the al-Qaeda-aligned Nusra Front. The FBI again closed that investigation, having discovered “minimal” contact. [New York Times’ Alan Blinder et al]

Whether Mateen was acting under Islamic State orders or seeking the group’s approval is “irrelevant” to Islamic State, suggests Rukmini Callimachi for the New York Times. For Islamic State, influencing foreign attackers to pledge allegiance to it before carrying out massacres “has become a core part of the group’s propaganda over the past two years” and is a “purposeful blurring” of the distinction between operations it has planned and those carried out by sympathizers.

“Lone wolf” attacks. President Obama has repeatedly warned about attacks by individuals on US soil while acknowledging that his administration “can’t stop them all.” Propagating its message online, writes Michael Crowley, enables Islamic State to “inflict blows on America from attackers who may be complete strangers.” Furthermore, the ready availability of firearms and the minimal training required to open fire on large groups of civilians at close range makes these attacks “simply too easy.” [Politico]

“Every lethal terrorist attack in the United States in the past decade and a half has been carried out by American citizens or legal permanent residents,” writes Peter Bergen, who are “operating either as lone wolves or in pairs” and “who have no formal connections or training from terrorist organizations such as al Qaeda or ISIS.” [CNN]

IRAQ and SYRIA

Airstrikes in the northwestern Syrian city of Idlib hit a market and other targets, killing at least twelve, local activists advised yesterday. [AP]

Islamic State claimed responsibility for suicide bombings in a mainly Shiite suburb of Damascus, Syria’s capital, which killed at least 20 people on Saturday. The Sayyida Zeinab areas is home to a shrine that is visited by thousands of Iraqi and Afghan Shiite militia recruits before they are assigned to the front lines in the fight against Islamic State. [NBC News’ Elisha Fieldstadt]

Islamic State attacked a military base east of Fallujah, Iraq, on Saturday, killing dozens of Iraqi government troops and allied Shia militia members. [Al Jazeera]

On the edge of Fallujah, Iraqi special forces are facing a complex network of booby traps. Col. Arkan Fadhil told reporters on Saturday that on the previous morning, alone, Iraqi engineering teams had encountered 25 improvised bombs over a stretch of just 500 feet. Disabling the explosives is slowing the progress of the Iraqi forces, who as of Saturday were within two miles of the city’s center. [Washington Post’s Loveday Morris]

Iraq is investigating allegations that Shiite militiamen supporting its army executed dozens of Sunni Muslim men from Fallujah. A number of arrests have already been made, a government spokesperson said today. Reportedly 643 Sunni men went missing between June 3 and 5 after being detained by the militiamen. Those who emerged from detention bore signs of severe torture. [Reuters’ Maher Chmaytelli and Ahmen Rasheed]

Over 4,000 more civilians have fled Fallujah after Iraqi government forces retook an important inroad over the weekend, the Norwegian Refugee Council reported this morning. This brings the total to 27,580 since the offensive to take back the city began in late May, with an estimated 50,000 remaining inside the city. [AP]

Despite over $1.6 billion in US funding, Iraq’s army “still struggles,” report Loveday Morris and Missy Ryan. Inadequate intelligence, logistical issues, corruption and poor leadership are the main “weaknesses,” they say. Foreign assistance has help to correct these, but Iraq will require “significant help for years to come if the army’s recent successes against the militants are to be maintained.” [Washington Post]

AFGHANISTAN

Afghan and Pakistani soldiers clashed at the main border crossing at the end of the Khyber Pass overnight, officials confirmed this morning. At least one Afghan soldier was killed. Both countries have blamed each other for starting the fight. [Reuters’ Ahmad Sultan]

Obama may not decide whether to change plans to almost halve US forces in Afghanistan before next month’s NATO summit, according to a diplomat and a US official. A decision had been expected at or before the summit. Defense Secretary Ash Carter is due to fly to Brussels this morning to meet with his NATO counterparts, and Afghanistan is expected to be high on the agenda. [Reuters’ Arshad Mohammed and Phil Stewart]

The present-day Taliban are “active on a variety of media platforms:” releasing audio files of news updates, and even launching a smartphone app for their Voice of Jihad website, report Ehsanullah Amiri and Margherita Stancati in the Wall Street Journal. This is a far cry from their pre-2001 days, when the group banned television, cinemas and photography as un-Islamic.

LIBYA

Libyan forces have taken back parts of Sirte, Islamic State’s main stronghold outside of Syria and Iraq, from the militant group, having gained control of a port late Friday. [CNN’s Hamdi Alkshali et al; Wall Street Journal’s Tamer El-Ghobashy and Hassan Morajea]

The Libyan army has appealed to Western government to provide weapons to help them drive home a victory in Sirte, particularly long-range weapons to overcome Islamic State snipers, who are hitting targets up to 2km away. Some intelligence support is currently being provided by a small team of US and UK advisers, spokesperson Brig. Gen. Ghasri has confirmed. [Financial Times’ Heba Saleh]

CYBERSECURITY, PRIVACY and TECHNOLOGY

WikiLeaks is to publish more of former secretary of state Hillary Clinton’s emails, founder Julian Assange said during an interview on Sunday. He did not specify when they would be leaked, or how many more emails WikiLeaks has yet to disclose following its launch of a searchable archive of 30,322 emails and email attachments in March. [The Guardian’s Mark Tran]

“Government secrecy, especially in matters of foreign policy and national security, is worse than ever, and the over-classification of information increases by the day.” Today is the 45th anniversary of the 1971 publication by the New York Times of the Pentagon Papers, a classified document setting out the history of US involvement in Southeast Asia and the “untruths” the public was told about it, writes Sandford J Ungar, a Lumina Foundation fellow and teacher of free speech at Harvard and Georgetown universities. He says that, decades later, the situation is worse. [Washington Post]

OTHER DEVELOPMENTS

A US government review board has rejected a Kenyan prisoner’s application for release from Guantánamo Bay, issuing a brief statement saying that the continued detention of Abdul Malik is necessary because he continues to pose a “significant threat” to US security. [AP]

CIA Director John Brennan supports and expects the release of the 28-pages, the only portion of a congressional report on 9/11 that remains classified, he told interviewers on Saturday. [The Hill’s Harper Neidig]

Baltic countries and Poland fear NATO’s plans to deploy on their territory are “too small and symbolic” to deter a Russian attack, report Robin Emmott and Andrius Sytas. The nations plan to put pressure on other ministers of the alliance to help them build an air defense system to protect them from Russian aircraft and missiles this week, a step which would likely be seen by Russia as further evidence that NATO intends to threaten its borders. [Reuters]

A man armed with weapons and explosive materials and heading for a Gay Pride parade in West Hollywood was arrested by Santa Monica police on Sunday morning, law-enforcement officials have confirmed. They also confirmed there was no known connection with Sunday’s attack in Orlando, Florida. [Wall Street Journal’s Zusha Elinson et al]

Police in Bangladesh have detained over 8,500 people in the first day of a four-day operation aimed at combating extremist violence against religious minorities and secular activists, they confirmed this morning. [Wall Street Journal]  In addition, at least 103 militants have been arrested. [Reuters]

A bomb attack in Beirut, Lebanon, wounded one person on Sunday. It is the first explosion to hit Lebanon since last November, when twin suicide attacks struck southern Beirut, killing at least 43. That attack was claimed by Islamic State. There has been no claim of responsibility for the latest attack so far. [AP]