Deadliest US mass shooting, ever; Puerto Rico SitRep; Libya strikes illustrate expansion of US ops; Q&A with ISIS-war deputy commander; and just a bit more...

“The worst mass shooting in modern American history.” At least 50 people are dead and more than 200 wounded after a gunman opened fire from the 32nd floor of a hotel and down on an outdoor concert crowd of more than 22,000 in Las Vegas Sunday night at about 10 p.m. local. NBC News calls it “the worst mass shooting in modern American history.”

The shooter, according to authorities, was Stephen Paddock, a 64-year-old white man from Mesquite, Nevada, about 80 miles northeast of Vegas.

Said one witness to NBC: “We heard what sounded like firecrackers going off. Then all of a sudden we heard what sounded like a machine gun... People kept dropping and dropping… People were getting shot one foot away from us. People were trying to save their friends. There were gunshots everywhere. Helping them would’ve meant that we got shot, too.”

Authorities are investigating how much Paddock may have planned all this out, including whether he specifically requested the room on the 32nd floor. But inside that room, “after using explosives to enter,” police found multiple weapons, NBC reports. CNN reports there were at least eight weapons in the room, including “multiple long rifles.”

But they can’t ask Paddock since Las Vegas Sheriff Joseph Lombardo told CNN this morning, “We believe the individual killed himself.” The whole situation is still developing, so this is understandable. But previous reporting, from NBC in particular, said Paddock was “killed by police… in the Mandalay Bay Resort.”

From the New York Times: “Several SWAT teams were sent to the hotel immediately after the first reports of the shooting at 10:08 p.m., and officers overheard on police radio reported being pinned down by gunfire. Shortly before midnight the Las Vegas police reported that ‘one suspect is down,’ and soon thereafter the police said they did not believe there were any more active gunmen.”

Added Las Vegas Police Undersheriff Kevin McMahill: "He was shot, but I cannot tell you that it was the police that shot him. He may have self-inflicted that gunshot wound. Those details are still emerging throughout our investigation."

While the investigations proceed, CNN reports that “So far, [the] massacre has no known link to overseas terrorism or terror groups, a US official with knowledge of the case said.” Read on, here.

From Defense One

Q&A: Deputy Commander of the War on ISIS // Ben Watson: Marine Corps Brig. Gen. Robert Sofge is helping to coordinate a two-front ground war in Iraq.

Waltzing Toward a Two-Front Global War // Christopher J. Bolan: The U.S. just might be one step away from a war with North Korea, and two from a fight with Iran.

Social Media is 'First Tool' of 21st-Century Warfare, US Lawmaker Says // Jack Corrigan: And buying Facebook ads is much cheaper than an F-35 fighter jet, said Sen. Mark Warner.

What Went Wrong With France's Deradicalization Program? // Maddy Crowell: By training at-risk youths in history, philosophy, literature, and religion, the government hoped to fight terrorism at its root.

Welcome to Monday’s edition of The D Brief by Ben Watson and Bradley Peniston. Happy 215th birthday, Washington Navy Yard, once the largest ordnance factory in the world. Have something you want to share? Email us. (And if you’re reading this on our website, consider subscribing. It’s free.)

Puerto Rico latest. As of 5 p.m. Sunday, the U.S. Army had sent more than 5,600 soldiers and civilians to the U.S. Virgin Islands and Puerto Rico, the Army announced.
The U.S. Army Corps of Engineers are “installing point generators across St. Thomas, St. Croix, and Puerto Rico” and “continue to provide oversight and management of the emergency power restoration and initial part of rebuilding the electrical grid in Puerto Rico.”
A Quartermaster company in San Juan is "providing laundry and shower support following the passing of the hurricane and continue to support more than 100 evacuees." And other units are "conducting route clearance operations" in the west and "transporting commodities, medical supplies, and fuel to distribution points throughout Puerto Rico."
DoD’s quick-read sitrep: “USNS COMFORT is expected to arrive tomorrow with 800 medical personnel and support staff to support 250 patient beds. ARG/MEU helicopters will install sandbag reinforcement of the Guajataca Dam spillway today; evacuations remain in effect for area residents. 721 of 1100 retail gas stations have re-opened. Sixty-five percent (+16%) of grocery & big box stores open. Ten of 10 airports open; eight sea ports are open (including Ponce); Roosevelt Roads remains closed with severe pier damage and debris. Major state roads continue to reopen in both directions.”
FYI: “NOAA reports moderate to heavy rainfall will move towards PR and the USVI by mid-week.”
Send in USS Ponce! The afloat forward staging base recently returned to Norfolk after a successful five-year mission in the Persian Gulf. Naval analyst Chris Cavas suggests that the 16,000-ton former amphibious assault ship, which happens to be named for a Puerto Rican city, should take up station in San Juan harbor, where it could provide “multiple agencies and officials the kind of situational awareness and communications facilities they need. The ship can refuel helicopters, support small craft, and provide berthing and feeding facilities for hundreds of passengers. Even better, the ship has nothing else to do—meaning it can stay as long as necessary—and she’s only three steaming days away.” Read on, here.

This weekend, within two days of ISIS leader Abu Bakr al-Baghdadi’s call for more attacks on the west, a 30-year-old Somali-born refugee is in custody after being “suspected of stabbing a policeman and injuring four pedestrians on Saturday” in Edmonton, Alberta, Canada. BBC: “Edmonton officials say the suspect could face terror and murder-related charges. They add that he had been known to police for believing in extremist ideology… Two injured pedestrians have since been released from hospital and the police officer is recovering from his wounds.”

And in France, a man “fatally stabbed two women outside Saint-Charles station in Marseille on Sunday” in an attack claimed by ISIS. He reportedly shouted “Allahu Akhbar” before each attack, then ran toward French soldiers, who shot him twice, killing him.
One more thing: French authorities traced the man’s fingerprints to “multiple fake identities,” The Guardian reports. Read on, here.  

An IED blast killed one member of the U.S-led coalition fighting ISIS in Iraq on Sunday, CENTCOM said later in the evening. Another unidentified service member was injured. “The names and circumstances surrounding the incident are being held pending notification of next of kin, and will be released at the discretion of the pertinent national authorities.”

For your eyes only: Wander through Raqqa, Syria, with the BBC’s Quentin Sommerville. “Mute the video, if you like,” he says. “It’s the devastation you need to experience.”

Take a second look at last week’s new U.S. strikes in Libya, via this take on expanded “lethal strikes outside a designated war zone and without explicit White House approval in advance,” by U.S. News’ Paul Shinkman.
Context: "the latest operation is unique in that it did not take place in an 'area of active hostilities,' a term the Obama administration used to clarify where the U.S. is and is not at war and, perhaps more importantly, where military commanders – not the president or his immediate team – would determine whether a drone strike or other deadly operation was appropriate."
What this seems to suggest: "The rules that governed Tuesday's strike show how much more power the military now has to determine where it can go after terrorist networks, and it follows recent reports that the administration seeks to to increase the authority of the military and the CIA to conduct drone operations. That the military can now carry out such operations raises new questions about the general limits of its power in Africa and elsewhere: What now stops the Defense Department from carrying out drone strikes wherever it wants?" Read on, here.

Trump ordered cyber attacks on North Korea months ago, the Washington Post reported this weekend. “As part of the campaign, U.S. Cyber Command targeted hackers in North Korea’s military spy agency, the Reconnaissance General Bureau, by barraging their computer servers with traffic that choked off Internet access.”
And another facet of this newly aggressive approach — triggered after a policy review in March — involved “instructions to diplomats and officials to bring up North Korea in virtually every conversation with foreign interlocutors and urge them to sever all ties with Pyongyang… So pervasive is the diplomatic campaign that some governments have found themselves scrambling to find any ties with North Korea.” More here.
But: new US-DPRK comms: Secretary of State Rex Tillerson said that the U.S. has established “direct lines of communication to North Korea, and his immediate goal is to ‘calm things down’ in the international standoff over the country's nuclear weapons program.” CNN, here.
But, part II: One day later, President Trump tweeted, “I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man...Save your energy Rex, we'll do what has to be done!” Is this a left hand-right hand problem? A good-cop, bad-cop ploy?

Trouble in Trumpistan? The White House wants to close the Taliban’s office in Qatar — but State Department officials are pushing back, filing an internal dissent memo arguing closing that office “would undermine U.S. interests in Afghanistan,” The Wall Street Journal reported Sunday. “Not having a line of effort with a clear focus on a political process seems contrary to his interests, as well as being bad policy,” one former U.S. official told the Journal.

A cyber defense system used by the Pentagon had its software reviewed by a Russian defense agency just last year, Reuters reported Sunday. The system, from Hewlett Packard Enterprise, is called ArcSight, and it “serves as a cybersecurity nerve center for much of the U.S. military, alerting analysts when it detects that computer systems may have come under attack. ArcSight is also widely used in the private sector.”
The Russian firm: “Echelon, a company with close ties to the Russian military, on behalf of Russia's Federal Service for Technical and Export Control (FSTEC), a defense agency tasked with countering cyber espionage.”
The big concern now: "Six former U.S. intelligence officials, as well as former ArcSight employees and independent security experts, said the source code review could help Moscow discover weaknesses in the software, potentially helping attackers to blind the U.S. military to a cyber attack."
FWIW: HPE officials insist “our source code and products are in no way compromised.” Read on, here.

September was the deadliest month of the year for Syrian civilians, Agence France-Presse reported Sunday. “At least 3,000 people including 955 civilians” were killed by coalition, Syrian regime or Russian aircraft, according to the Syrian Observatory for Human Rights. More, along with a battlefield update of where some of the more intense fighting is still taking place, over here.

Lastly today: ISIS-themed fake Lego sets pulled from store in Singapore. The made-in-China sets “depict violent scenes that show figurines carrying the ISIS flag, launching sticks of dynamite and firing AK-47s, with one set even including a plastic figurine of a decapitated head.” Read on, here.