Overnight: a military op in Tikrit; Mosul delayed; Is mil retirement system too sweet? Better know a Sunni, Shiite; Too soon? SNL’s ISIS skit; And a bit more.

A massive operation to clear ISIS from Tikrit kicked off overnight: The Iraqi security forces launched a large offensive with Sunni and Shiite fighters to take back the town of Tikrit from ISIS. AP’s Sinan Salaheddin from Baghdad: “Al-Iraqiya television said that the forces were attacking Tikrit from different directions, backed by artillery and airstrikes by Iraqi fighter jets. It said the militants were dislodged from some areas outside the city. Several hours into the operation, it gave no details…

Any operation to take Mosul would require Iraq to seize Tikrit first because of its strategic location for military enforcements… While the TV said Shiite and Sunni tribal fighters were cooperating in Monday's offensive, Tikrit is an important Sunni stronghold, and the presence of Shiite forces risks could prompt a backlash among Sunnis.” More here.

Reuters' Dominic Evans: “[Prime Minister Haider al-Abadi] gave Islamic State supporters what he said was one last chance to lay down their arms, or face ‘the punishment they deserve because they stood with terrorism.’ … Iraq's air force was carrying out strikes in support of the advancing ground forces, who were being reinforced by troops and militia...” More here.

NYT’s Omar Al-Jawoshy and Tim Arango: “Monday’s attack, which officials said involved more than 30,000 fighters supported by Iraqi helicopters and jets, was the boldest effort yet to recapture Tikrit and, Iraqi officials said, the largest Iraqi offensive anywhere in the country since the Islamic State took control of Mosul… Success in Tikrit could push up the timetable for a Mosul campaign, while failure would most likely mean more delays.” More here.

Meantime, a Syrian rebel group—the first to receive U.S. weapons—collapsed yesterday after an assault on their position in Aleppo. The WaPo’s Liz Sly: “The rout of Harakat Hazm, whose name means Steadfastness Movement, culminated months of clashes with the al-Qaeda-linked Jabhat al-Nusra… Hazm, which once claimed to have 5,000 fighters, had received U.S. weapons under a separate covert program launched last year by the CIA… Hazm’s defeat will muddle the wider effort to combat extremism by leaving large swaths of northern Syria that had once been controlled by moderates in the hands of Nusra.” More here.

The fight against ISIS “is a third world war by other means,” Jordan’s King Abdullah told CNN’s Fareed Zakaria yesterday. Video and full transcript, here.

The spring offensive in Mosul has been delayed. The plan was for the Iraqis, with pointed encouragement from the U.S., to re-take Mosul from ISIS this spring, and controversy surrounded the U.S. Centom briefing earlier this month that detailed the operation. But for now, the whole thing is off: the Iraqis aren’t ready. The Daily Beast’s Nancy  Youssef from Friday evening: “The U.S. military’s goal to retake Iraq’s second largest city from the self-proclaimed Islamic State has been pushed back several months at least, defense officials told The Daily Beast. That’s a major shift for the Pentagon, which recently announced that the first major ground offensive in the war against ISIS could come in the next few weeks… Now, those officials say, Fall is more realistic. And even that date was tenuous.” Read the story in TDB, here.

The WSJ’s Julian Barnes and Adam Entous on the “evolving plan:” “…the U.S. would use its air power in the coming months to further isolate Mosul and weaken the hold of Islamic State fighters on the city. Under this approach, U.S. airstrikes would be focused on picking off Islamic State leaders to undermine their ability to command and control their forces.

“Kurdish forces have already cut off one of the main approaches into Mosul from Syria. Another approach could be cut off from Anbar province. Iraqi forces could focus first on clearing Islamic State militants out of pockets of Anbar before turning to Mosul, which is expected to more difficult.

“Under this scenario, ground operations in Mosul would take place in the fall, if not later. The U.S. believes that a force of around 20,000 fighters will be needed to liberate and hold Mosul, officials said.” Read the rest here.

Recordings suggest that Emirates and the Egyptian military pushed Morsi out. The NYT’s David Kirkpatrick, here.

You think you know Sunnis and Shiites? Then take this little 17-question quiz by The Christian Science Monitor, which does these kinds of things so well, right here.

Probably “too soon:” Saturday Night Live on Saturday spoofed the Toyota ad with the dad sending his kid off into the U.S. military and instead sends guest host Dakota Johnson into the arms of ISIS in a bit that perhaps rightly pissed off half the Internet. That vid and story in AdWeek, here.

And: Molly O’Toole reported on Wisconsin Gov. Scott Walker’s appearance at CPAC, including his campaign’s effort to walk back or contextualize a stumble on how he would ISIS as commander-in-chief.

Walker stepped in it with this line last week: “If I can take on 100,000 protesters, I can do the same across the world.” That, here.

Welcome to Monday’s edition of The D Brief, Defense One's first-read national security newsletter. If you’d like to subscribe to The D Brief, reply to this email and let us know, subscribe here or send us a holler at glubold@defenseone.com. Please send us your tips, your tidbits, your scoops and stories, your think tank reports and best of all your candy, but send it to us early for maximum tease. And whatever you do, we hope you'll follow us @glubold and @natsecwatson.

Twas the place to be: IDEX has become a must-attend event for defense firms and consultants and as Defense One's Marcus Weisgerber tells us, it's a conversation with a powerful decision maker that could translate into billions of dollars into weapons sales. Weisgerber, who was there this past week: For defense firms, it’s simply all about ‘being there” at an event like the International Defence Exposition and Conference, better know as IDEX. You never know who will show up: presidents, princes, defense ministers, generals and admirals from all corners of the world are here. And flashiness matters even for companies and even countries that like to keep low profiles. The goal is to catch the eye of a power player, one who could ink a multimillion or even multibillion dollar deal. Plus, it doesn’t hurt that some countries have acquisition systems that simply depend on the depth of a wealthy individual’s pockets, and not approval by the U.S. Congress.”

Kentucky Sen. Rand Paul won the Conservative Political Action Conference’s straw poll, as he has for the past two years. But none of the potential 2016 candidates emerged as a national security stand-out, and a few stumbled. Defense One politics editor Molly O’Toole: “It is not necessarily surprising that national security played such a large role at this year’s CPAC. But the fact that it got bigger cheers than even Cruz’s ‘defunding every blasted word of Obamacare’ is a notable reflection of how current global security crises have shifted the political tides for the GOP…but as Republican National Committee Chair Reince Priebus noted at the conference: there are some 600 days until Election Day 2016.“ Read the rest, here.

Is military retirement too sweet a deal? Thems are fightin’ words to some, both in and out of the military, who believe the current retirement system, which almost everyone agrees is generous, rightly pays retirees for the sacrifices service members have endured over a 20-years-or-more career. But defense leaders will say it’s fiscally unsustainable and it’s outdated. It’s the third rail of politics: questioning the benefits men and women in uniform receive. But the results of the military compensation review are in, so let the debate begin. Tim Kane, research fellow at Stanford University’s Hoover Institution--and not Sen. Tim Kaine, as incorrectly noted in a previous version of today's The D Brief--says the current system is overkill.

Kane, writing in War on the Rocks: “Retiring from the U.S. military is a sweet deal for the 17 percent of veterans who are allowed to serve for twenty years on active duty. Too sweet.

“For decades, critics and top brass have warned that the Pentagon’s defined benefit pension (earned after 20 years of service) is growing exponentially more expensive.

“…the recommendation issued in late January 2015 by the Military Compensation and Retirement Modernization Commission’s final report offers no analysis of the distortionary effects of the status quo. It may be the first major commission in half a century to recommend leaving the defined benefit pension in place.” Read the rest of Kane’s argument, along with some revealing charts, here.

Who’s doing what today? The Chief of Naval Operations Adm. Jon Greenert is participating in the USNR Centennial Kickoff celebration at the Pentagon at 10a.m…. Commander of the 173rd Airborne Brigade in Italy talks land forces for today’s conflicts at the Center for Strategic and International Studies at 10 a.m. Catch that live here … CNO Adm. Jonathon Greenert and Navy Reserve Chief Vice Adm. Robin Braun will be attending the Navy Reserve Centennial today at the Pentagon at 10 a.m. … Director of National Intelligence James Clapper is in New York City for a 1 p.m. discussion on the intel community at the Council on Foreign Relations. Live stream for that one, here. … and retired Gen. John Allen talks the future fight against ISIS at the Atlantic Council at 5 p.m. That streams live, here.

By the way: We said last week that Fort Leavenworth was in Missouri. We KNOW it's in Kansas, we were just testing you. Thank you for all the cards and the letters, and apologies for the brain-lock.

An army officer sums up what makes Marines so different: hint: it’s that whole everybody-a-riflemen thing. Excerpt of USA’s Col. Dan Bolger’s book, “Death Ground: Today’s American Infantry in Battle,” on USMC81.com, here.

Last week we read about an Afghan woman who is a taxi driver; today, it’s about female Afghan police officers and the struggles they encounter against ideas embedded in Afghan society. The NYT’s Alissa Rubin writes the story on Page One that jumps to a big double truck inside the paper: “…As the tale of Afghan policewomen shows, repressive views of women were not just a Taliban curse, but also a deeply embedded part of society. Now, as Western troops and money flow out of Afghanistan, the question is just how much the encounter with the West and its values has really changed the country, and whether any of the foreign ideas about the status of women took hold.” More here.

Read the WaPo’s Sudarsan Raghavan’s bit last week about Sara Bahayi, Afghanistan’s first female taxi driver who drives a… you guessed it… Toyota Corolla (they’re ALL Toyota Corollas)…  Raghavan: “…[Bahayi] is 38. She’s unmarried. She’s outspoken. In this highly patriarchal society, where women are considered second-class citizens and often abused, Bahayi is brazenly upending gender roles.” Worth the read, here.  

There was an avalanche in Panjshir province north of Kabul this weekend that may have claimed as many as 200 lives. The heartbreaking pictures on The Telegraph, here.

“Spock” was once a sergeant in the Army Reserve. The beloved Leonard Nimoy passed away last week at the age of 83. Catch him in one of his earliest roles, this one a 1954 Marine Corps video on “combat psychiatry,” thanks to Business Insider’s Armin Rosen, here.

Israeli Prime Minister Benjamin Netanyahu is in DC ahead of the controversial speech he’s expected to deliver to Congress tomorrow. Six Israeli generals came out against the speech, saying that it will embolden Iran and breaks too many White House dishes. The WSJ’s Nicholas Casey and Joshua Mitnick: “…The comments, a rare public rebuke by retired military leaders before an election, came on the eve of Mr. Netanyahu’s departure to Washington.”

Said Amnon Reshef, a former general who headed Israel’s armored corps: “When the Israeli prime minister argues that his speech will stop Iran from obtaining nuclear weapons, he is not only misleading Israel—he is actually strengthening Iran… The American people see the rift between Israel and the administration. The Israeli public sees it and more important: the mullahs in Iran see it as well.” More here.

The day after Netanyahu’s visit to Congress is when the real pressure on the White House will be on display. The Atlantic’s Jeffrey Goldberg on the Israeli prime minister’s “perverse genius” undermining possible breakthroughs on the Iran nuclear issue: “Netanyahu obviously believes that Obama doesn’t have his, or Israel’s, back. There will be no convincing Netanyahu that Obama is anything but a dangerous adversary. But if a consensus forms in high-level Israeli security circles (where there is a minimum of Obama-related hysterics) that the president has agreed to a weak deal, one that provides a glide path for Iran toward the nuclear threshold, then we will be able to say, fairly, that Obama’s promises to Israel were not kept…” More here.

One workaround for a hypothetical Marine amphibious assault in an anti-ship missile threat zone: “converting supertankers into highly survivable, if not unsinkable, amphibious support ships.” Retired Navy and Foreign Service Officer William Stearman, writing in the Marine Corps Gazette: “What we are looking at is a 265,000 long ton (long tons, with a full fuel load) tanker 1,075 feet long with a 170-foot beam and a hull depth of 80 feet… this huge hull ‘reduces the probability of hull girder failure from an under keel attack.’ Second it could easily survive multiple side torpedo hits. Third, its huge volume and heavy structure would defeat most HE (high explosive) weapons and, and it would provide the stand-off distances and the volume/weight needed to defeat Soviet style HEAT (high explosive anti-tank type shaped charge) ASCMs (anti-ship cruise missiles) or high impact speed APHE (armor piercing high explosive.) warheads.” Read the rest, here.