Nearly a dozen dead in downtown Istanbul; US bombs Mosul cash stash; SOTU prep; Precision guidance for the B61 nuke; and a bit more.

Bombing hits Turkish tourism hub, killing nearly a dozen and wounding 15 others near the Hagia Sophia in the heart of Istanbul. President Tayyip Erdogan said a Syrian suicide bomber was to blame, and two Turkish officials said there was a high probability the Islamic State was behind the attack. However, as Reuters notes, “Islamist, leftist and Kurdish militants, who are battling Ankara in southeast Turkey, have all carried out attacks in the past.”

The location of the attack “is home to some of Istanbul’s most visited monuments, including a Byzantine-era former hippodrome, or racetrack; the Hagia Sophia, a sixth-century Greek Orthodox basilica and now a museum; the Blue Mosque; and the Topkapi Palace, built by the Ottoman sultans,” adds the New York Times.

Six Germans, one Norwegian, and a tourist from Peru were among those injured, the Associated Press reports. And so far, Denmark and Germany have warned their citizens to avoid crowded places outside tourist spots in Turkey. The EU’s foreign policy chief, Federica Mogherini, expressed solidarity with Turkey, and called for Europe and Turkey to “step up our efforts to counter extremist violence.” AP has more, here.

A U.S. airstrike in Mosul, Iraq, on Sunday destroyed “a building containing huge amounts of cash ISIS was using to pay its troops and for ongoing operations,” two U.S. defense officials told CNN Monday, adding their estimate of currency eliminated from the bombing was in the millions.

“Two 2,000-pound bombs destroyed the site quickly,” CNN reported, adding, “The U.S. considers the Mosul strike extremely sensitive, as the building is in an area where civilians are also located, and there was a significant risk of civilian casualties.”

U.S. officials apparently took the risk anyway, banking on the strike’s longer-term impact on the group’s finances. “Officials would not say how the U.S. learned of the location. But after getting intelligence about the so-called ‘cash collection and distribution point,’ U.S. aircraft and drones watched the site for days trying to determine when the fewest number of civilians would be in the area.”

A bit more on that risk assessment: “U.S. commanders had been willing to consider up to 50 civilian casualties from the airstrike due to the importance of the target. But the initial post-attack assessment indicated that perhaps five to seven people were killed.” Read the rest, here.

And violence is on the uptick in southern Iraq this week, the country’s “Shiite heartland” that has largely been spared attacks from ISIS, reports the AP from Basra. “A Basra security official said an Iraqi military division of about 8,000 troops redeployed from the region in late 2014 to join the fight against IS, along with a police battalion of about 500 troops, leaving nine incomplete police battalions and only one army battalion for the entire Basra province, which has a population of about 3 million.”

The result, the official said, “has been a wave of armed robberies targeting homes, cars, jewelry stores and currency exchanges, as well as a resurgence in tribal clashes and an increase in drug trafficking from neighboring Iran to Gulf Arab states.”

Meanwhile in Ramadi, “The support of the people will be harder to rebuild than the houses and offices,” writes former Gen. Ray Odierno advisor, Emma Sky, channeling the input from a former Iraqi parliamentarian who is now tasked with “historic national reconciliation.” Just how much of a tall order is that gig? Read on to find out.

It’s State of the Union night in America this evening, so why not get straight to the heart of U.S. national security tensions by digging into five problems you won’t hear from President Barack Obama’s annual address, compiled by the Heritage Foundation’s Justin Johnson. Starting things off is his plea to increase defense spending, increase the Army’s size—more on the dynamics on that front here—boost the size of the Navy, keep the prison at Guantanamo Bay open, and two other points of contention over at The Daily Signal right here.

And while we’re focused on the White House, Fox Business channel just demoted GOP 2016 contenders Carly Fiorina and Rand Paul to the undercard debate this Thursday. In response, Paul says he is boycotting the event. The Washington Post has more, here.

From Defense One

America’s new plan to fight ISIS online. The State Department will diversify its one-way approach, while other agencies reach out to Silicon Valley. Technology Editor Patrick Tucker reports, here.

Learn what America’s longest-serving general most fears. Gen. John Kelly, commander of U.S. Southern Command, goes “over the side for the last time” with 45 years of wisdom on U.S. war-fighting and its future. Read his exit interview with Politics Reporter Molly O’Toole, here.

Go inside the lab where invisibility cloaks are made. So far, the closest thing we have to making things disappear is using prisms to keep hidden things hidden. The Atlantic, here.

Can Americans — and their next president — see past short-term campaign promises to save Afghanistan? Former ambassador Lincoln Bloomfield and Oleg Svet make their argument that building Afghan security requires a long-term U.S. commitment, here.

Obama prepares a ‘non­traditional’ State of the Union address. Even as the House preps a pair of foreign policy bills, Republicans prepare for their retreat. That from National Journal, here.

Why ISIS cannot be negotiated with. The Atlantic Council’s H. A. Hellyer takes issue with Jonathan Powell, who argued in The Atlantic that talking to terrorists has brought peace in the past. But Hellyer says the Islamic State really is different. Read that, here.

Welcome to Tuesday’s edition of the The D Brief, by Ben Watson and Bradley Peniston. Get your friends off on the right foot in 2016 by telling them to subscribe here: http://get.defenseone.com/d-brief/. Want to see something different this year? Got news? Let us know: the-d-brief@defenseone.com.

On Capitol Hill, Senate Armed Services Chairman John McCain alleges the Army broke the law when it allowed Eric Fanning to act as service secretary while his nomination awaits Senate confirmation, Defense News reported Monday. “McCain, a frequent critic of the administration, said Obama’s appointment of Fanning as acting secretary, while Fanning was the nominee, breached the Federal Vacancies Reform Act of 1998.”

The Pentagon response: “Mr. Fanning’s designation as acting secretary of the Army was consistent with longstanding executive branch interpretation of the Federal Vacancies Reform Act…Members of the Senate Armed Services Committee, however, expressed some concerns about that interpretation of the Act. As a show of comity to address these concerns, Fanning has agreed to step out of his acting role to focus on achieving confirmation in the near future.”

Meantime, “Army Undersecretary Patrick Murphy will serve as acting secretary in the interim. Fanning will serve as a special assistant to Defense Secretary Ash Carter.” More here.

A bit more from the Department of Revolving Doors: Todd A. Weiler,  former Army aviation officer from 1987 to 1991 and a combat veteran of Operations Desert Storm and Desert Shield, “has been nominated as the next assistant secretary of defense for manpower and reserve affairs,” Military Times reports. Weiler is no stranger to the office, having “served as deputy assistant secretary of the Army for manpower and reserve affairs from 1993 to 1999” after serving as the White House Liaison for the Department of Defense in 1993.

Remember that submarine-launched missile North Korea showed off in late December, just days before its bomb test quaked the entire region? Analysts tell Reuters the footage was fake. Read their explainer, which breaks down the video frame-by-frame to find a big load of BS, here.

On the deterrence side of the Pyongyang threat, the New York Times reports this morning that the Pentagon, in conjunction with the U.S. Department of Energy, was working on a mock version of the nation’s first precision-guided atom bomb just last fall.

Writes the Times: “The United States military is replacing the fixed tail section of the B61 bomb with steerable fins and adding other advanced technology. The result is a bomb that can make more accurate nuclear strikes and a warhead whose destructive power can be adjusted to minimize collateral damage and radioactive fallout.” But this “build-it-smaller approach has set off a philosophical clash among those in Washington who think about the unthinkable.” More here.

Philippines court approves U.S. defense presence: AP: “The Philippine Supreme Court on Tuesday declared as constitutional a defense pact that allows American forces, warships and planes to temporarily base in local military camps, in a boost to U.S. efforts to reassert its presence in Asia as China rises to regional dominance.” Read more, here.

Better late than never? From the Roanoke Times: “Lynn Craig returned safely from Iraq in 2005, but a three-page letter he wrote to his father during his tour with the Marines wasn’t delivered until last week.” Read on, here.