500 more US troops to Iraq?; ISIS fired a mustard-agent shell; Russia negs Syrian no-go zone; How the USAF preps for cyber war; and just a bit more.

The U.S. military wants 500 more troops for Iraq’s push toward Mosul, The Wall Street Journal reported Wednesday evening. If approved, it would bring the total number of authorized American troops in Iraq to about 4,900. For the bean counters: “The Pentagon also maintains up to 1,500 additional U.S. forces that it doesn’t acknowledge as part of its Iraq force, most at the U.S. Embassy in Baghdad or on temporary assignments,” WSJ writes. “The new deployment would bring the overall U.S. presence to as high as 6,400. The 500 would be in addition to roughly 400 new personnel the U.S. sent to Iraq in early September to prepare for the Mosul offensive.”

“The U.S. move would come in the wake of an operation that began Tuesday by Iraqi forces in Shirqat, a town north of Baghdad, to further degrade Islamic State supply lines into Mosul,” the Journal reports of an offensive that has now delivered Iraqi troops to the center of Shirqat, 60 miles south of Mosul, Reuters reports this morning: “The army, backed by local police and Sunni Muslim tribal fighters, were still clashing with the ultra-hardline jihadists after taking control of the mayor's office, the municipal building and the hospital, said a source from the Salahuddin Operations Command, which oversees military operations in the area.”

Baghdad’s forces and Iranian-backed Shi'ite Muslim militias surrounded the city in recent days, but Reuters writes that the Shi’ite militias have not entered Shirqat—where “tens of thousands of civilians were thought to be trapped” as ISIS fighters are reportedly resisting “in groups of three and four from inside houses.”

Other key locations coalition troops are expected to march through en route to Mosul include Hawija, east of Shirqat, and Tel Afar, west of Mosul, Reuters adds.

Life in Mosul is as you’d expect at this stage, the BBC reported off a former resident of the city who managed to escape and bring his personal diary along with him. BBC has excerpts of that to set the scene, here.

And the Washington Post echoes the findings from the former resident, adding some unfortunate and predictable developments on a graffiti-driven resistance that has formed in the city, which involves just one letter—M— “for the Arabic word ‘mukawama,’ meaning resistance,” reports WaPo’s Loveday Morris and Mustafa Salim from Baghdad.

ISIS now stands accused “of firing a shell with mustard agent that landed at the Qayyara air base in Iraq Tuesday where US and Iraqi troops are operating,” CNN reported Wednesday. “The shell was categorized by officials as either a rocket or artillery shell. After it landed on the base, just south of Mosul, US troops tested it and received an initial reading for a chemical agent they believe is mustard. No US troops were hurt or have displayed symptoms of exposure to mustard agent.”

Food for thought: Why doesn’t ISIS brag about their CW use? asked The New York Times’ C.J. Chivers on Twitter Wednesday. His question sparked a lively debate on the merits and perils of such a move for the group, and it’s worth a quick read, here.

Back stateside, the U.S. Senate voted Wednesday to keep selling munitions to Saudi Arabia because...Iran. Roll Call reports on yesterday’s Senate hearing, which was intended to be about a “proposed $1.15 billion weapons sale includes 153 Abrams tanks, 20 armored vehicles, over 400 machine guns and more than 6,600 rounds of ammunition,” but the hearing centered far more on Iran’s growing influence and antagonism throughout the Middle East, and barely even mentioned the Saudi-led war in Yemen—the principal reason Sens. Rand Paul, R-Kentucky, and Chris Murphy, D-Connecticut, opposed the sale.

"If you’re serious about stopping the flow of extremist recruiting across this globe, then you have to be serious that the...brand of Islam that is spread by Saudi Arabia all over the world, is part of the problem,” Murphy said.

Replied Sen. Lindsey Graham, R-S.C.: “Saudi Arabia has shared intelligence with us that has made Americans safe. They have allowed us to use their air bases in times of conflict. They are all in against ISIL and they are a great ally …against Iran. …The pluses outweigh the minuses.” More from Roll Call, here, and Reuters, here.

So how’s Yemen going? 26 civilians were just killed overnight in another possibly errant airstrike. For the record, the war in Yemen has killed more than 10,000 people so far. Reuters has more, here.

Russia says no-go on Kerry’s partial no-fly-zone over NW Syria. State Secretary John Kerry insists the cease-fire in Syria is not dead, and is working like hell to keep it alive. But this morning, “Russian Deputy Foreign Minister Sergei Ryabkov dismissed Mr. Kerry’s call to prohibit aircraft from flying in northern Syria to prevent further attacks on aid convoys and prevent errant strikes, calling it ‘not functional,’” WSJ reports from Moscow.

Russia’s stated beef with the proposal: “Moscow didn’t believe Washington capable of exerting control over the various rebel groups arrayed against Syrian President Bashar al-Assad as part of a cease-fire deal.” More here.

Surprise, surprise: Assad’s allied airstrikes continue to pound Aleppo, unleashing “the heaviest air strikes in months against rebel-held districts of the city,” Reuters reports.

Remember that Russian drawdown? More than 4,500 Russians voted from Syria last week’s parliamentary election, analysts from the Conflict Intelligence Team said Wednesday after getting a glimpse of election data.

ICYMI: Here’s a look at Russian military activity across the globe, “from the South China Sea to Sevastopol,” via the U.S. Naval Institute, writing nearly a week ago.

The skinny: “It may not be 1984 again, but it certainly is not 1994 or 2004 either. Incorporated into what appears to be an overarching strategy to assert Russian primacy in their self-identified ‘near abroad’ the Russians are doing several things simultaneously, the most important of which may well be the large-scale exercises in Crimea as part of an apparent larger strategic war game. While many may argue the relative merits of various aspects of Russian power, sanctions, diplomatic isolation and other lines of effort, there is no denying that Russia is synchronizing a strategy to keep Europe off-balance, potential allies encouraged and possible enemies deterred from the Baltic to the Black Sea and further afield.” Much more on all that, here.  

From Defense One

How the U.S. Air Force is Rapidly Mobilizing For Cyber War // Tech Editor Patrick Tucker: New ideas about defense and new tables of organization are reshaping the service’s ideas about battle.

Progress or Oppression—You Decide, Obama Tells the UN in His Final Address // The Council on Foreign Relations’ Stewart M. Patrick: From mass migration to North Korea's nukes, Obama's lofty speech contained little guidance about how to resolve the world’s intractable problems.

Welcome to Thursday’s edition of The D Brief by Ben Watson and Bradley Peniston. On this day in 1939, Soviet and German soldiers paraded together in victory down the streets of Brest-Litovsk, Poland. (Send your friends this link: http://get.defenseone.com/d-brief/. And let us know your news: the-d-brief@defenseone.com.)

Russia and China have wrapped up their largest joint naval exercise ever, which they held — natch — in the South China Sea. Reporting for Popular Science, Jeffrey Lin and Peter W. Singer explain what they did Sept. 12-19, and why it matters, here.

Oh, and the Chinese are also racing to space. “After years of investment and strategy, China is well on its way to becoming a space superpower—and maybe even a dominant one,” Singer reports, noting the upcoming mission to put the first human spacecraft on the moon’s dark side.

But meanwhile, look out for pieces of the first Chinese space station, which has come loose from its orbit and is expected to break up and crash to Earth sometime next year.

If only there was a truck-mounted laser that could vaporize the pieces...oh, wait, a Chinese firm is now offering the Low Altitude Guard II, which uses 30-kilowatt directed-energy to shoot down drones and the like.

Yet more national-security leaders denounce Trump: “A group of 75 retired career Foreign Service officers, including ambassadors and senior State Department officials under Republican and Democratic presidents over nearly a half-century, has signed an open letter calling Donald Trump ‘entirely unqualified to serve as President and Commander-in-Chief,’” reports the Washington Post. Add that letter to the list of unprecedented things about the 2016 election: it is unheard-of for top career diplomats, many of whom have never publicly even identified with a specific political party, to criticize a candidate.

Meanwhile, the Guardian unloads on Trump’s notion that the U.S. should have seized Iraq’s oil, citing experts who judge it “wildly stupid, almost impossible and…a war crime.”

Having a hard time keeping up with the high-profile anti-Trumpers? James Fallows has a list.

So the B-21 is now called the “Raider,” but here are 4,600 other names submitted for the Air Force’s newest shiny object. (Oh, you thought the USAF would just tell you what they were? No, Gizmodo pried them from the service’s grasp via FOIA.)

The U.S. must be the world’s policeman, says former NATO Secretary General Anders Fogh Rasmussen, writing in the WSJ, and taking a few thinly veiled jabs at President Obama: “The world needs such a policeman if freedom and prosperity are to prevail against the forces of oppression, and the only capable, reliable and desirable candidate for the position is the United States,” he writes.

The jab: “From my former positions as prime minister of Denmark and secretary-general of NATO, I know how important American leadership is. We desperately need a U.S. president who is able and willing to lead the free world and counter autocrats like President Putin. A president who will lead from the front, not from behind.” More here.

Lastly today: On Wednesday’s episode of Sesame Street, “R” stood for refugee as Deputy State Secretary Tony Blinken spoke with Grover—who has a few comedic lines about the UN—to explain how kids can help welcome refugees into their schools and communities. Catch their exchange, here.