7 dead on USN destroyer; US troops in the crosshairs in Syria; Tensions rise with Moscow; Attacks on Muslims in US, UK; and just a bit more...

Seven dead on a USN destroyer. In the deadliest collision of a Navy warship in decades, the bow of a Philippines-registered cargo ship rammed into the starboard side of USS Fitzgerald about 2 a.m. off Japan’s southern coast, leaving seven American sailors dead and three more injured, including the commanding officer, who was medevaced off the ship. More from the New York Times, here.

The ship itself was in danger of sinking, and was saved by the herculean efforts of crew roused from sleep into mortal peril, Navy leaders tell Navy Times, which has some details of the damage-control efforts, here.

How did it happen? Amateur sleuths are already digging into publicly available ship-tracking details, but the final word — as well as official blame — will come from the no-doubt-months-long Navy investigation.

But in the meantime, read this piece by former destroyer skipper Bryan McGrath, who explains the intricacies of maneuver at sea, starting with rules of the road, reading ships’ anticollision lights, how a radar picture goes bad, and more. Via War on the Rocks, here.

The names of the deceased: Gunner’s Mate Seaman Dakota Kyle Rigsby, 19, from Palmyra, Virginia; Yeoman 3rd Class Shingo Alexander Douglass, 25, from San Diego, California; Sonar Technician 3rd Class Ngoc T Truong Huynh, 25, from Oakville, Connecticut; Gunner’s Mate 2nd Class Noe Hernandez, 26, from Weslaco, Texas; Fire Controlman 2nd Class Carlos Victor Ganzon Sibayan, 23, from Chula Vista, California; Personnel Specialist 1st Class Xavier Alec Martin, 24, from Halethorpe, Maryland; and Fire Controlman 1st Class Gary Leo Rehm Jr., 37, from Elyria, Ohio.

Says Doctrine Man: "I look at their names and their ages and think of all those they join in giving their very last. Rest In Peace."

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Welcome to Monday’s edition of The D Brief by Ben Watson and Bradley Peniston. On this day 45 years ago, Woodward and Bernstein published their first story on the Watergate scandal. Got tips? Email us at the-d-brief@defenseone.com. (And if you’re reading this on our website, consider subscribing. It’s free.)

A series of alarming new developments in Syria this weekend put the U.S. military squarely in the crosshairs of Moscow’s, Damascus’ and Tehran’s own militaries.

We begin a bit south of ISIS-held Raqqa, Syria, where a U.S. Navy F/A-18 shot down a warplane for the first time in 18 years on Sunday. “The Pentagon said the downing of the aircraft came hours after Syrian loyalist forces attacked U.S.-backed fighters, known as the Syrian Democratic Forces, in the village of Ja’Din, southwest of Raqqa,” the Washington Post reported.

As the paper’s Beirut bureau chief Liz Sly noted: This is a “huge escalation, [and] entirely inevitable.”

The reax from Damascus: The U.S. is obviously supporting ISIS. “The attack stresses coordination between the US and ISIS, and it reveals the evil intentions of the US in administrating terrorism and investing it to pass the US-Zionist project in the region.”

The episode has inflamed the U.S.-Russian relationship, according to Moscow—which called the U.S. Air Force response a "massive violation of international law and de facto military aggression."

“Before it downed the Syrian plane, the U.S. military used a ‘deconfliction’ channel to communicate with Russia, Syria’s main ally, to prevent the situation from escalating,” WaPo writes off a post-event statement from the Pentagon.  

In response, Moscow has chosen to “suspend the use of a military hotline that the United States and Russia have used to avoid collisions in Syrian airspace,” The New York Times reports. “All flying objects, including planes and drones of the international coalition, detected west of the Euphrates, will be followed by Russian air defense systems as targets,” the Russian Defense Ministry said in a statement.

The reax from the U.S.-backed SDF: "If the regime continues attacking our positions in Raqqa province, we will be forced to retaliate...and defend our forces," said SDF spokesman Talal Selo in a statement.

For what it’s worth: The last U.S. Air Force air-to-air kill: USAF Lt. Col. Michael H. Geczy on May 4, 1999 over Bosnia, noted Jeff Schogol of Military Times. ABC News filled in a few details, writing that episode featured a U.S. F-16 shooting down a Serbian MiG-29.

ABC News reminds readers: “Over the last four weeks, the U.S. has conducted three airstrikes at pro-regime Assad forces, backed by Iran, that have moved into a de-confliction zone around the town of at Tanf in southwest Syria, which is the location of a coalition training base for local forces fighting ISIS.”

And concerned officer (@pptsapper) brings up good point: "While I'm not terribly sad that Assad lost a jet, I'm a tad curious as to how much we can continue to do under only an AUMF..."

Iran fired missiles into eastern Syria this weekend, nearly two weeks after the ISIS-claimed attacks in Tehran. “The strikes are the first time Iran has fired missiles at another country in three decades and represent a major escalation of Iran's role in the war in Syria,” CNN reported.

Iran appeared to have used its new Zulfiqar ballistic missile in the strikes, Joseph Dempsey of the International Institute for Strategic Studies wrote on Twitter. He’s been following open-source info on the episode closely, pulling out the lat/longs of the strike along with purported Iranian UAV footage of the hit in the vicinity of Deir ez-Zour, Syria.

Optics: “This was NOT a message for ISIS—it was for the US, Israel and Saudi Arabia,” said Nadav Pollak, a counterterrorism analyst for the Anti-Defamation League, sharing the Instagram post celebrating the strike by saying, “We will slap [ISIS] in the face.”

Iraqi forces on Sunday initiated a concerted effort to push ISIS out of Mosul’s Old City. “The assault began at dawn, with airstrikes and a push by Iraq’s counterterrorism forces into the neighborhoods of the old city. It was met with fierce resistance by Islamic State fighters, according to commanders, suggesting that the battle, the most vicious phase in the long fight for Mosul, could go on for days or weeks,” NYT’s Tim Arango reports.

Sunday’s offensive sparked a car bomb rush by ISIS, which reportedly sent more than a dozen at ISF almost immediately.

“Intense gun battles broke out after they entered,” WaPo reported Sunday from Mosul in what seems to be the best available reporting from the ISIS-held city. “With the winding streets making car bombs more difficult to mobilize, the militants compensated with antitank weapons and mortar fire, which crashed down into streets behind the front lines. Snipers also waylaid the advance.” Worth reading the full report, here.

Here’s a map of what turf is believed to remain in ISIS hands, via the Nineveh Media Center.

Watch footage of a Javelin fired on ISIS positions in West Mosul over the weekend, here.

For what it’s worth: "India is the Second Largest Source of Components Used by the Islamic State to Make Explosives," The Wall Street Journal reported this weekend off of a new report from researchers at the London-based Conflict Armament Research. The India-made products include detonators, detonating cord, and safety fuses. Full report (it’s a 6MB PDF file), here.

The weekend in extremism, UK and U.S. edition: The driver of a van plowed into pedestrians outside a London mosque, injuring at least ten people. “The driver, a 48-year-old white man, was grabbed at the scene by locals and pinned down until police arrived,” Reuters reports this morning, adding, “The attack is the fourth since March in Britain and the third to involve a vehicle deliberately driven at pedestrians.”

The driver reported shouted “I wanna kill more people, I wanna kill more Muslims,” according to Reuters.

And back stateside, a 17-year-old Muslim female was kidnapped and beaten to death with a bat in Fairfax, Va. The suspect, “Darwin Martinez Torres, 22, of Sterling has been arrested and charged with murder,” WaPo reports, here.

European flashpoint alert: U.S., British troops conducted a NATO exercise in a place known as the Suwalki Gap, just southwest of the Russian enclave in Kaliningrad, Reuters reported. “Over two days, U.S. helicopters and British aircraft took part in exercises that also involved troops from Poland, Lithuania and Croatia in a simulated defense of the potential flashpoint.”

And about that flashpoint: “The frontier runs for 104 km (65 miles) through farmland, woods and low hills... If seized by Russia, it would cut off Estonia, Latvia and Lithuania.”

Said U.S. Lieutenant General Ben Hodges to Reuters: "The gap is vulnerable because of the geography. It's not inevitable that there's going to be an attack, of course, but ... if that was closed, then you have three allies that are north that are potentially isolated from the rest of the alliance."

Read a bit more about the Suwalki Gap, via this analysis from STRATFOR back in 2015.    

Another insider attack in Afghanistan has left seven Americans wounded. “The incident occurred around 2 p.m. local time, during a training exercise at Camp Shaheen in Mazar-e Sharif. The attacker, a commando assigned to the Afghan army's 209th corps, allegedly fired three rocket-propelled grenades at the Americans before continuing the attack with two M4 carbines, an Afghan defense officials told Military Times. The assailant was later shot dead by an American armed with a pistol.” More here.

Defense industry news: “Raytheon to restart SM-2 missile line after $650 million sale,” Reuters reported Sunday.

And Lockheed Martin is reportedly close to a “$37 billion-plus deal to sell F-35 jet to 11 countries,” including Australia, Denmark, Israel, Italy, Japan, the Netherlands, Norway, Turkey, South Korea, Britain and the United States.

“The memorandum of understanding being negotiated between Lockheed and the customers aims to procure 135 or more jets in fiscal year 2018 for delivery in 2020 for about $88 million per jet.” More here.

Lastly today: Let us celebrate the extreme patience of 25-year-old San Francisco resident, Luca Iaconi-Stewart. Why’s he so interesting? He “spent the last nine years in his parents’ house building an exquisitely precise replica of an Air India Boeing 777 jet made entirely from cut-up paper folders,” General Electric’s public relations wing reported Friday. “The plane is complete down to details like bolts, hydraulic pipes and hinges. It has amenities like seatback entertainment systems, food carts and also the hidden crew ‘rest module’ that most passengers, even those in first class, never get to see.”

GE spoke to him ahead of the Paris Air Show, and you can find that—along with video clips of the impressive airliner—here.

You can also check out a preview of the airshow via Defense One’s Marcus Weisgerber, who will be attending this year’s event, writing about it in his Global Business Brief newsletter, here.