NATO, nervous; Russia builds up in Kaliningrad; Mattis sends thank-you to Saudi; Your suggestions for the Army’s next slogan; and just a bit more...

As NATO’s leaders gather, whither the alliance? “NATO summit meetings were once ritualistic events, with the member nations assembling to proclaim that the alliance had never been stronger and pledging to work together on the security issues of the day,” writes the New York Times. “In the Trump era, however, they have become anxiety-producing confrontations where the main object is to avoid long-term damage to the military alliance.”

What to expect: CNAS’ Rachel Rizzo, writing in Defense One: “Donald Trump’s first full NATO summit is expected to be contentious, if not downright hostile. The U.S. president’s sole goal for Brussels appears to be hammering allies on their defense spending.” (Exhibits A, B, C, etc.)

Just out: the latest NATO spending figures. The alliance released this fact sheet, with charts, on Tuesday morning. (A reminder: no matter how many times Trump says alliance members upped their spending after he took office, most of the increases were in the works before his election.)

The Atlantic Council offers some advice to the alliance, in the form of a joint letter from James Stavridis, John R. Allen, Giampaolo di Paola, and a host of other former NATO military and diplomatic leaders. Read that, here.

And the summit is just the start. Rizzo continues: “It’s even less clear what he wants to do with the remainder of his Europe trip, which includes meetings with a severely weakened Theresa May and Russian strongman Vladimir Putin...Trump will enter this visit knowing that the prime minister is in a fragile position. Because of this, he’ll likely show a lack of interest, or even worse, bully her.”

From Defense One

Russia Building Up Military Sites on Poland’s Border Before Trump-Putin Meeting // Patrick Tucker: Satellite photos show new structures and other bunker improvements in the Baltic Sea exclave of Kaliningrad made in the run-up to the NATO summit.

What to Expect from Trump’s Marathon Week of Diplomacy // CNAS’ Rachel Rizzo: Allies are right to be worried.

Trump’s Message to NATO // Krishnadev Calamur, The Atlantic: ‘We’re the schmucks paying for the whole thing.”

America and North Korea Are Having Two Different Conversations // Kathy Gilsinan, The Atlantic: One country’s “productive” talks are another’s “gangster-like” demands.

The Lesson of the Great War: Stay Engaged, America // Eliot A. Cohen: A century after the guns fell silent, the United States risks replicating the errors of the past.

DHS Aims to Turn Mobile Devices into No Phishing Zones // Frank Konkel, Nextgov: The Homeland Security Department and 16 other agencies are upgrading their mobile device security.

Welcome to this Tuesday edition of The D Brief  by Bradley Peniston and Ben Watson. And if you find this useful, consider forwarding it to a friend or colleague. They can subscribe here for free. On this day in 2017, the city of Mosul, Iraq, was liberated from the Islamic State terror group. See that offensive, mapped, in this 80-second animation we made last year, here.

America’s special operators in Iraq have an official U.S. government Twitter handle: @SOJTFOIR (Special Ops Joint Task Force-Operation Inherent Resolve). One item you’ll find in that feed....
OIR’s commander, Lt. Gen. Paul Funk, has written an op-ed to trace a bit of what’s been done in the past year, and what he likes about what he sees moving forward.
Some of that, via Military Times: Years ago the U.S. was involved in operations where the Iraqis were content to let the coalition lead while they idly sat on the sidelines. This is no longer the case,” Funk writes. “For years our Iraqi partners viewed themselves by their tribal, sectarian and religious background first, with few feeling their country was what defined them. We now interact not with Sunnis, Shias or Kurds; but with people who identify themselves as Iraqis first and embody the patriotism associated with that moniker.”
And on the ISF’s biggest accomplishment, and what lies ahead: The liberation of Mosul broke the back of ISIS in Iraq and gave the Iraqi military and the Iraqi people the confidence to work together and rid their country of this scourge permanently.” Read on, here.

However, the task of getting rid of ISIS permanently has a ways to go yet. A recent analysis suggest a new heartland of the terror group’s insurgency appears to be forming in what’s called the Hamrin-Diyala-Tigris triangle. The authors are from the Armed Conflict Location & Event Data Project.
The report’s title: “The Reconstitution of the Islamic State’s Insurgency in Central Iraq.”
The quick read: “The [ISIS] insurgency is now concentrated along a geographic belt in Iraq which has been described as the ‘Colonization Zone,' which is composed of largely rural Sunni-majority areas in the provinces of Salahuddin, Kirkuk, Diyala, and Nineveh, as well as the cross-sectarian outskirts of Iraq’s capital, Baghdad.”
Contributing factors to IS’s persistence: “The typographical features of Kirkuk and the ‘colonization zone’ more generally are another important factor which offer advantages to IS militants by offering them areas where they can take refuge and stage attacks. These include the vast farmlands of Salahuddin, the forests and orchards of Diyala, and the far-reaching Hamrin mountain range, which cover large parts of Kirkuk, Salahuddin, and Diyala governorates.” So no more held cities; but plenty of countryside to hide among between attacks. Read the report in full, here.
And Monday saw a few more airstrikes on hiding ISIS fighters. Iraqi Joint Operations Command said Monday coalition aircraft killed 20 fighters holed up in a tunnel near Badush, northwest of Mosul. A bit more (in Arabic), here.

In a very unusual product from the Pentagon on Monday, SecDef Mattis (age 67) penned an extended “thank you” letter to the Saudi King via his more active son, Crown Prince Mohammed bin Salman (age 32), for supporting the Afghanistan peace process.
The letter’s opening: “Your Royal Highness, I read with great interest and appreciation the Custodian of the Two Holy Mosques, King Salman's statement supporting President Ghani's reconciliation efforts in Afghanistan and calling for a renewed ceasefire and end to hostilities there. The Imam of the Grand Mosque, the Organization of Islamic Cooperation, and the Muslim World League’s subsequent statements further reinforced this message and helped magnify its importance to the Afghan people.” Read it in full, here.

SitRep on Afghanistan territorial control: The Foundation for the Defense of Democracies is still hard at work maintaining their mapping project showing contested turf in the country where America has been at war since 2001. The latest count is still not a pretty picture for Kabul.
Another FDD product worth a click: A review of where the war in Syria is heading, with FDD’s senior counselor John Hannah and director of research David Adesnik. That 43-minute podcast begins here.

What do you think? Should Fort Riley offer more than $750 “for information regarding the kidnapping and sexual assault” of a 1st Infantry Division soldier? The Army offers $3,000 to find lost night vision goggles, writes the man behind WTFNation. “We need to do better,” he says.

ICYMI: U.S. troops are on the ground in Yemen in the war against al-Qaeda. American JTACs are accompanying UAE soldiers and their Shabwani Elite militia in the mountains of southern Yemen, the Washington Post’s Sudarsan Raghavan reported on location in a #LongRead this past weekend.
Just don’t expect the Pentagon to elaborate due to “operational security and the safety of our forces” in Yemen. Definitely worth the click — with video clips and maps — here.
The war in Yemen could be staffed a bit longer now that the UAE has extended conscription to 16 months from 12, Reuters reported Monday. “The UAE introduced mandatory military service in 2014 for Emirati men. It kept participation for women, who can serve only for nine months, optional and requiring approval of their legal guardians. Men who hold a high school diploma or its equivalent will serve 16 months instead of 12, while those who do not have a high school qualification will continue to serve for two years.” A bit more, here.

For your eyes only: Watch as dozens of aircraft passed over Buckingham Palace this morning as the Royal Air Force celebrated 100 years of history. Video via the BBC, here.

Finally today: Your feedback at last! We polled our readers on what they think the U.S. Army’s new recruiting slogan should be — since the service is changing “Army strong” to something else. Thanks for sending in your replies.
And now here are a few of the ones we received, in no particular order:

• First to fight; last to leave; always on duty.
• Army: homegrown strength projected.
• For your country.
• Freedom's Force.
• Once Army always Army.
• America’s Defenders.
• Defenders of Freedom.
• Be One With The (Armed) Force.
• The Army: America’s Might.
• No Barriers. No Limits.
• A Force for Freedom.
• Your country, your opportunity.
• Corey Lewandowski's "Womp Womp"
• Great intentions ruined by implementation.
• Be all you can put up with.