Mixed signals on eve of Moscow visit; US rounds up Russian hackers; Another NorK nuke test expected; Secret drones in the Nevada desert; and just a bit more...

Anonymous U.S. officials give more mixed signals on the U.S.-Russian relationship just as Secretary of State Rex Tillerson heads to Moscow. “The U.S. raised the stakes [on Russia] significantly on Monday when a senior U.S. official said Washington has made a preliminary conclusion that Russia knew in advance of Syria's chemical weapons attack last week,” the Associated Press reports. Caveats: “Yet the U.S. has no proof of Moscow's involvement, said the official.”

So what’s the evidence? AP reports the unnamed officials said a “drone operated by Russians was flying over a hospital as victims of the attack were rushing to get treatment. Hours after the drone left, a Russian-made fighter jet bombed the hospital in what American officials believe was an attempt to cover up the usage of chemical weapons.”

What’s more, “The U.S. official said the presence of the surveillance drone over the hospital couldn't have been a coincidence, and that Russia must have known the chemical weapons attack was coming and that victims were seeking treatment.”

Still, a second nameless U.S. official “cautioned that no final American determination has been made that Russia knew ahead of time that chemical weapons would be used.”

Meanwhile, Tillerson offered a tough rhetorical line on the Syrian regime and its Russian patron: “It is clear to us the reign of the Assad family is coming to an end," he told reporters in Italy this morning before departing for Moscow. "We hope that the Russian government concludes that they have aligned themselves with an unreliable partner in Bashar Al-Assad."

Read more on the mixed signaling via U.S. News’ Paul Shinkman, here.

Defense Secretary James Mattis has this message for Syrian President Bashar al-Assad: “the United States will not passively stand by while Assad murders innocent people with chemical weapons,” he said in a statement released Monday.

Mattis also shared a bit of battle damage assessment from Thursday’s strike on Syria’s Shayrat air base: “the strike resulted in the damage or destruction of fuel and ammunition sites, air defense capabilities, and 20 percent of Syria’s operational aircraft. The Syrian government has lost the ability to refuel or rearm aircraft at Shayrat airfield and at this point, use of the runway is of idle military interest.”

Mattis finished with a warning: “The Syrian government would be ill-advised ever again to use chemical weapons.”

That was close. At Monday’s press briefing, White House spox Sean Spicer declared that if the Syrian military dropped barrel bombs, the U.S. might take more actions like Thursday’s cruise missile strikes. For context: the Assad regime dropped some 13,000 barrel bombs last year and another 1,000-plus in the first two months of this year, according to the Syrian Network for Human Rights.

After reporters pressed him about whether he really meant to draw such a wide red line, the White House eventually conceded that Spicer meant “barrel bombs that contained chemical weapons like chlorine”—and not the ubiquitous, conventional — and still deadly — ones.

That was close (part 2). Spicer tripped over Assad’s full name, prompting UAE-based journalist Harold Doordbos to joke, “Narrow escape for Bashar al-Assad here. U.S. is after Basa al-Ashar.” Clip, here.

From Defense One

In Syria, Russia Falls Victim to Its Own Success // Julia Ioffe: Moscow's rogue client has destroyed the country's ability to present itself as an indispensable arbiter in the conflict.  

Why ISIS Declared War on Egypt's Christians // Mokhtar Awad: The group has been exporting Iraq-style sectarian tactics to the Arab world's most populous country.

Trump's Unlawful Attack in Syria // Garrett Epps: Trump launched an attack on Bashar al-Assad's government without the legal authority to do so.

Seven Dubious Arguments for Not Fighting Assad // Shadi Hamid: Intervention may not be the right choice. But we should at least be clear about what we are—and aren't—debating.

Welcome to this Tuesday edition of The D Brief by Ben Watson and Bradley Peniston. #OTD1951: President Harry S Truman fires Gen. Douglas MacArthur as commander of U.S. forces in Korea. Send us your news: the-d-brief@defenseone.com.

North Korea warns of nuclear strike if provoked by U.S. warships, Reuters reports this morning. "Our revolutionary strong army is keenly watching every move by enemy elements with our nuclear sight focused on the U.S. invasionary bases not only in South Korea and the Pacific operation theatre but also in the U.S. mainland," North Korea's official Rodong Sinmun newspaper said. (Reminder: a U.S. aircraft carrier battle group is heading for nearby waters.)

In a statement from the foreign ministry, North Korea said, “We never beg for peace but we will take the toughest counteraction against the provocateurs in order to defend ourselves by powerful force of arms and keep to the road chosen by ourselves.”

In response, South Korea’s acting President Hwang Kyo-ahn “ordered the military to intensify monitoring and to ensure close communication with the United States.” He also warned that Saturday is the 105th anniversary of the birth of Kim Il Sung, the North's founding father and grandfather of current ruler, Kim Jong Un, Reuters reports. “A military parade is expected in the North's capital, Pyongyang, to mark the day. North Korea often also marks important anniversaries with tests of its nuclear or missile capabilities in breach of U.N. Security Council resolutions.”

Adds Reuters: “The North is seen ready to conduct its sixth nuclear test at any time, with movements detected by satellite at its Punggye-ri nuclear test site.” More here.

For your ears only: All about nukes, the history of President Truman inheriting them and U.S. citizens coming to terms with their terrifying power, via the MacArthur “genius” award-winning podcasters at WNYC’s Radiolab (scroll to the 4:45 mark, past the sponsors to where the show really starts), here.

The U.S. has been quietly rounding up alleged Russian hackers, NBC News reported Monday. “At least six Russians have been arrested in Europe on international warrants over the past several months, according to McClatchy Newspapers. The most recent arrest was Friday in Barcelona, where a 32-year-old Russian computer programmer was nabbed.”

About this fella: His name is Pyotr Levashov, he’s 32, and the Spanish National Police have accused him of “scamming and data theft." In a phone conversation from jail, he reportedly told his wife his arrest was "linked to Trump's election win."

The U.S. response: “It is to-be-determined whether [Levashov] had anything to do with the WikiLeaks hack or the Russian role in the election. He was being looked at on other cyber issues, so he will be asked about the elections," a nameless official told NBC. Read more on Levashov and five other programmers with international arrest warrants out, here.

ICYMI: Who among us hasn’t lied on our SF-86? That’s a joke, because the answer had better be none. But the White House may have a bit of an issue with Jared Kushner, who omitted not just a meeting with Russians when he filled out his security-clearance application form—but “dozens of contacts with foreign leaders or officials in recent months,” The New York Times reported last week. Kushner’s lawyer said it was an accident, and he’ll be submitted revised forms soon.

Batten down the hatches. The U.S. military is seeing Russian naval activity around Europe “that we didn't even see when it was the Soviet Union. It's precedential activity," Navy Admiral Michelle Howard, who heads NATO's Allied Joint Force Command in Naples and commands U.S. naval forces in Europe and Africa, told Reuters this weekend. “Howard said the Russian naval maneuvers had been matched by increased persistent cyber attacks by Moscow, and a steady number of unprofessional ‘fly bys’ by Russian aircraft of U.S. and other allied vessels at sea.” More here.

RIP Green Beret Staff Sgt. Mark R. De Alencar, the U.S. soldier who died fighting ISIS this weekend in Afghanistan. The Pentagon released his name shortly before his body was delivered to Delaware’s Dover AFB late Monday. He was a 7th Group team member, age 37, born in Edgewood, Maryland. Read more about his family, friends and his high school stomping grounds, via the Baltimore Sun, here.

The view from the home of the Airborne and Special Forces. Long lines are greeting entrants at the gate of Fort Bragg, N.C., the Fayetteville Observer reported late last week. What’s the holdup? “soldiers [have been] removed from gate guard duty and placed back into their line units to focus on training,” ending a 2010 program to backfill for a shortage of uniformed servicemembers as the Afghan surge kicked off.

But seven years later, the troops are gearing up for a newer war—the one on ISIS, where the 2nd Brigade Combat Team from Bragg’s 82nd Airborne Division are fighting in Iraq—and no backup is coming for those less-manned entry points.

Why? “Fort Bragg officials say they are not authorized to hire more civilian security guards to work at the access control points. And it’s not possible to have additional military police posted at gates.”

Said post spox Tom McCollum: “The MPs are already stretched thin with training for deployments and patrolling throughout the installation,” he told the Observer. He then added, “By the way, if folks on the installation would slow down and pay attention to safe driving habits, maybe some of the MPs would be freed up from traffic patrols.” More here.

Also on Fort Bragg: Driverless cars taking soldiers to the hospital for physical therapy, scheduled visits, etc. Pictures and more from the Army’s Applied Robotics for Installations and Base Operations project, or ARIBO, here.

The U.S. Air Force “just announced a massive and shadowy drone-related contract for work out in the Nevada desert,” TheDrive’s Joseph Trevitheck reported Monday. “Unusually worded, the multi-billion dollar drone services contract possibly points to a new, shadowy unmanned aircraft—and a lot of them.”

To begin: “This contract with URS Federal Services is worth $3.6 billion, but the program, whatever it is, isn’t expected to end until the spring of 2034. That’s 17 years for those keeping score. The math works out to more than $210 million per year, on average, over that period or $17.5 million every month...the URS Federal Services' contract could potentially cover the full costs of running multiple squadrons of pilotless planes for nearly two decades.” Read on, here.

What Leahy amendment? The Trump administration wants to sell “up to a dozen A-29 Super Tucano aircraft” to Nigeria for the Boko Haram fight, the BBC reports. “The deal, which is not yet official, will require approval from Congress.” And that could be problematic considering a U.S. law that precludes military training or other assistance to countries with shoddy human rights records, like Nigeria.

BBC: “The deal, said to be worth up to $600m (£490m), was agreed by the Obama administration, but was reportedly halted on the day it was due to be sent to Congress, after a catastrophic incident involving the Nigerian military. About 90 people, mainly women and children, were killed in January when the Nigerian Air Force mistakenly bombed a camp in the country's north-east, which was hosting thousands of those who had fled Boko Haram.” More here.

Lastly today: a public service announcement. It’s a little UXO (unexploded ordnance) pro tip from police in Washington state: “Someone brought us an old grenade. Please don't do that,” the Edmonds PD said on Twitter Monday. “If you find one, leave it alone and call. We can bring Bomb Squad to you.”

One last thing, while we’re on found military objects: “Who Dumped These Fighter Planes in the Middle of Nowhere?” Popular Mechanics asked about a week ago.

The objects in question: “two F-14 Tomcat fighters and at least one F-4 Phantom II. The planes are missing their engines—F-14s were equipped with two huge General Electric F110 afterburning turbofan engines, while the older F-4s had two General Electric J79 turbojets. The wings were removed and are sitting in a separate pile. The electronics, particularly nose-mounted radars, have been stripped out as well as most of the cockpit controls, seats, and instrumentation.”

It’s unknown where the jets were discovered, “but the accents imply the location is somewhere in the South. The planes have apparently been there for years—some have trees growing out of them.” Story here; video here.