Deceased: Nemesio Rubén Oseguera Cervantes, 60, aka “El Mencho.” U.S. authorities had offered a $15 million reward for information leading to his capture. 

He led the Jalisco New Generation Cartel, which was known by its Spanish initials CJNG. He was injured in a shootout during a capture mission led by special forces in Tapalpa, Jalisco, in west-central Mexico; he later died en route to a hospital in Mexico City, the Associated Press reported Monday from Guadalajara. Six other cartel members were killed in the operation, which was supported by U.S. intelligence—but not U.S. troops—and yielded several armored vehicles and “rocket launchers capable of shooting down aircraft,” Mexico’s defense ministry said in a statement. At least three Mexican troops were killed in the initial shootout as well. 

The CJNG cartel was “notorious for trafficking fentanyl, methamphetamine and cocaine to the United States and staging brazen attacks against government officials who challenged it,” AP reports, citing a Justice Department announcement on the group from last month. “Cartel members responded with violence across the country, blocking roads and setting fire to vehicles.” Photographer Ulises Ruiz posted two dozen images of road blocks and post-shootout carnage to Getty on Sunday.

The cartel’s post-raid chaos extended to some nearby airports and affected flights from Air Canada, Delta, American Airlines and Alaska Airlines, Reuters reported Sunday. Axios has a bit more.

Less than two days from Trump’s next State of the Union address, his advisors are discouraging new military strikes against Iran in order to shift his political fortunes in the U.S., Reuters reported this weekend. “A senior White House official said that despite Trump's bellicose rhetoric there was still no ‘unified support’ within the administration to go ahead with an attack on Iran.” It’s a point several U.S. newspapers highlighted last week, as we noted atop Friday’s newsletter. 

With the next round of U.S.-Iran talks slated for Thursday, experts told the Times Iranian officials seem to view “capitulating to Washington’s demands on uranium enrichment and ballistic missiles as riskier to its survival than going to war.” 

Iranian officials are also reportedly preparing their proxies for retaliatory attacks abroad should Trump launch strikes on Iran, U.S. and other security officials told the Times on Sunday. 

White House officials have discussed “four separate aims” in using the U.S. military against Iran, so Nancy Youssef of The Atlantic spoke to current and former defense officials to game out each of the four paths—quick strikes, kill or capture operations targeting select leaders, destroying Iran’s ballistic missiles as well as paramilitary bases, and destroying what remains of its nuclear program—in an essay published Saturday.  

Legal consideration: “Any U.S. military strike on Iran under the current circumstances—either in relation to the dire human rights situation within Iran or its damaged nuclear program—would (once again) violate international law’s bedrock prohibition on the use of force,” three experts wrote Saturday in Just Security. “Other States are legally bound not to support or assist in any U.S. military action against Iran, and any potential agreement reached on Iran’s nuclear program under credible threat of U.S. force could be considered legally void,” they added atop their argument. Read the rest, here. 

For what it’s worth: Iran and Russia reached a formerly-secret deal to supply Tehran with 500 advanced shoulder-fired missile systems over the next three years, the Financial Times reported Sunday. However, the first delivery isn’t expected until 2027, Reuters reports. 

The White House foreign-policy strategy has been shaken up slightly in the wake of Friday’s Supreme Court decision to strike down Trump’s global tariff regime, rejecting the view that a presidential declaration of emergency is unreviewable by the courts because that would represent a “transformative expansion” of the president’s authority over tariff policy. But the decision could have other applications as well, since the Justice Department “makes similar claims in use of military domestically,” former Pentagon counsel Ryan Goodman noted Friday. 

Notable: “This decision doesn't say you can't issue tariffs,” economist Justin Wolfers pointed out in an interview with the BBC. “It says the president has to go through Congress to do it. So it's all about the unilateral power of our ‘King.’”

Key consideration: Trump’s entire foreign policy is based on threatening other countries with tariffs. And the New York Times showed Friday that the White House is using the military to carry out an effective blockade of Cuba, which is strangling a country that could run out of oil by mid-March and trigger all sorts of instability for the region. One notable detail from Trump’s pressure on Cuba: “the Trump administration has stopped short of calling its policy a blockade…which legally could be interpreted as an act of war,” the Times reports. 

And that has the potential to raise several questions, including: How does Friday’s Supreme Court decision affect the Pentagon’s Cuban blockade? Does the SCOTUS decision cast the U.S. military and Coast Guard’s tanker seizure operations around Cuba on more of a piracy light rather than legally-sanctioned activity? Trump’s Cuban blockade extends from another national emergency he declared in late January, claiming “the Cuban communist regime supports terrorism and destabilizes the region through migration and violence.” However, any potential court challenge would not materialize before the estimated mid-March timeline for Cuba to run out of oil nationwide. 

Cubans are already “struggling with frequent blackouts, shortages of gasoline and cooking gas and dwindling supplies of diesel that power the nation’s water pumps,” the Times reported Friday. “Trash is piling up, food prices are soaring, schools are canceling classes and hospitals are suspending surgeries.”

“You cannot suffocate a people like this,” Mexico President Claudia Sheinbaum said two weeks ago. Mexico is one of the last lifelines the Cuban people have to the outside world via humanitarian aid shipments, which include petroleum. Last month, Trump directly threatened tariffs on any nation providing oil to Cuba, and in early February specifically called out Mexico in this regard. 

Trump lashed out angrily at the 6-3 SCOTUS decision Friday, claiming “the court has been swayed by foreign interests and a political movement that is far smaller than people would ever think.” He also said he would impose a new global tariff regime of 10% on all imports under a law called Section 122 that allows a president to do so for a limit of 150 days. “I have the right to do tariffs, and I’ve always had the right to do tariffs,” he insisted to reporters Friday when asked why he can’t just work with Congress to come up with a plan. “I don’t have to,” he replied. 

The following day, he raised his new but temporary global tariffs to 15%, which Reuters reports is “the maximum level allowed under the law.” Also worth noting: “No president has previously invoked Section 122, and its use could lead to further legal challenges,” according to Reuters.  

Related reading: 

• French President Emmanuel “Macron says US Supreme Court tariff ruling shows it is good to have counterweights to power in democracies,” Reuters reported Saturday; 
• “EU loses patience following Trump’s latest tariff threat,” Politico reported Sunday; 
• “China, India Among Winners After US Court Blocked Trump Tariffs,” Bloomberg reported Sunday; 
• “Gold rises and stocks fall as global trade faces new Trump tariff threat,” the Financial Times reported Monday; 
• And the Wall Street Journal explains “Why Tariffs Aren’t Shrinking the U.S. Trade Deficit,” reporting Monday. 

Trump said Saturday he is sending a hospital ship to Greenland, but Denmark’s military chief rejected the plan the following day saying there is “no need for special health care efforts” on the Danish island Trump has been looking to acquire for several months. 

Greenland reax: “Please talk to us instead of just making more or less random statements on social media,” Prime Minister Jens-Frederik Nielsen said in a statement. “Trump’s idea of sending an American hospital ship here to Greenland has been noted. But we have a public healthcare system where treatment is free for citizens,” he added. 

Trump included an image of the Navy’s U.S.N.S. Mercy in his social media announcement. However, “As of late January, the 1,000-bed hospital ship was firmly in drydock at Alabama Shipyard in Mobile, where it has been undergoing scheduled maintenance since July 2025,” maritime industry blog gCaptain reported this weekend. And “her sister ship USNS Comfort [is also] moored at the Mobile shipyard.” AP has a bit more.

See also: “Danish military evacuates U.S. submariner who needed urgent medical care off Greenland,” also via AP, reporting Sunday. 

Welcome to this Monday edition of The D Brief, a newsletter focused on developments affecting the future of U.S. national security, brought to you by Ben Watson with Bradley Peniston and Thomas Novelly. It’s more important than ever to stay informed, so we’d like to take a moment to thank you for reading. Share your tips and feedback here. And if you’re not already subscribed, you can do that here. On this day in 1778, Friedrich von Steuben arrived in Valley Forge, where the Prussian officer would help bring skill and discipline to the Continental Army.

Around the Defense Department

WH struggles with gigantic spending-boost proposal. White House staffers are struggling to accommodate Defense Secretary Pete Hegseth’s January proposal to increase defense spending by about 50 percent, to $1.5 trillion, in the 2027 budget, the Washington Post reported on Saturday. 

“The idea ran into internal criticism from several other officials, including White House budget chief Russell Vought, who warned about its potential impact on the widening federal deficit, said the people, who spoke on the condition of anonymity to reflect internal deliberations. Since Trump agreed to the higher number, White House aides and defense officials have run into logistical challenges surrounding where to put the money, because the amount is so large, the people said.” Read on, here.

Two weeks late, and counting: The Trump administration is two weeks past the statutory deadline to send its spending proposal to Congress.

Developing: Hegseth is set to meet with Anthropic’s CEO, who has insisted that the Pentagon may not use its AI tools for two things: the mass surveillance of Americans and fully autonomous weaponry. “Anthropic knows this is not a get-to-know-you meeting," a senior defense official told Axios. "This is not a friendly meeting. This is a sh*t-or-get-off-the-pot meeting." 

Axios: “Claude is the only AI model available in the military's classified systems, and the most capable model for sensitive defense and intelligence work. The Pentagon doesn't want to lose access to Claude but is furious with Anthropic for refusing to lift its safeguards entirely.” More, here.

All eyes on Air Force leaders after a year of chaos and change. “Last March, the customarily lively halls of the Air Force's largest warfighting conference felt more like a ghost town,” writes Defense One’s Thomas Novelly. “Military attendance at the Air and Space Forces Association’s Warfare Symposium just outside of Denver had dwindled” after a travel ban, a scuttling of major service initiatives, and a vacuum at the top. “Now, as the conference returns to Colorado this week, all of that has changed. Airmen and guardians have been approved to travel for the events, said Amy Hudson, the association’s spokesperson.” Read on, here.

More reading:

• “New Army office aims to quickly develop and scale soldier ideas,” reports Defenese One’s Meghann Myers;
• “An MQ-20 drone just teamed up with an F-22 for mock combat missions,” Novelly reports; 
• “Embraer joins Northrop to devise autonomous boom system for KC-390 tanker,” reports Defense One’s Lauren C. Williams.

Birds and nerds of the defense industry: General Atomics announced Monday it has nicknamed its YFQ-42 drone wingman “Dark Merlin.” The company says it was inspired by “deadly falcons” and “the wizardry of Merlin from Arthurian legend, paying homage to the somewhat supernatural new era of semi-autonomous air combat.” 

Similarly, Anduril, whose company name is based on a sword from J.R.R. Tolkien's “The Lord of The Rings” fantasy books, calls its CCA offering “Fury,” which is the original name given to the aircraft by Blue Force Technologies, which was later acquired by Anduril in 2023. (There’s also a Silicon Valley startup called Valar Atomics, which—like Palantir and Anduril—is yet another defense-focused reference to “Lord of the Rings” mythology.)

Related/unrelated: Industry veteran Northrop Grumman went a different direction with its contribution to the CCA field, “Project Talon,” which is reportedly a nod to the Air Force’s T-38 trainer aircraft. 

Additional reading: 

• “Palantir, Which Is Powering ICE, Says Immigration Crackdown May Hurt Hiring,” 404 Media reported Wednesday; 
• “Federal judge accuses Trump administration of 'terror' against immigrants in scathing ruling,” the Associated Press reported Thursday; 
• “Former top general [Stanley McChrystal] calls military's removal of trans troops a costly mistake,” NPR reported Saturday; 
• “The U.S. Military Is Reviving Microbes from 40,000-Year-Old Ice,” 404 Media reported Friday; 
• And Defense Secretary Pete “Hegseth frames Trump policies as ‘biblical’ in address to Christian broadcasters,” Religion News reported Friday.