The D Brief: Why Yemen strikes ended; Gitmo flights, tallied; Spectrum battle; Turkey’s PKK disbands; And a bit more.

Behind Trump’s Yemen retreat: The U.S. military nearly lost “several” F-16s and an F-35 fighter jet to air defense systems during Defense Secretary Pete Hegseth’s aborted Operation Rough Rider, U.S. officials told the New York Times. The air campaign ran from March 15 to May 5, when President Trump decided he “had had enough,” according to the Times.

Trump ordered a halt to those U.S. airstrikes on May 5. The following day he informed reporters at the White House, “We will stop the bombings and they have capitulated. But more importantly, we will take their word: they say they will not be blowing up ships anymore,” he said. But behind the scenes that week, the Times reported on Monday, “The militant group in Yemen was still firing at ships and shooting down drones, while U.S. forces were burning through munitions.”

Fine print: In exchange for a halt in U.S. strikes, the Houthis allegedly agreed to “no longer target American ships in the Red Sea,” but they did not agree “to stop disrupting shipping that the group deemed helpful to Israel,” the Times reports. That likely contributed to the top five international shipping firms telling the Wall Street Journal last week they were in no hurry to return their vessels to the Red Sea.

The limits of U.S. airpower: By the time of Trump’s halt, the U.S. had lost three Super Hornet aircraft and nearly two dozen Reaper drones during combat operations against the Houthis, who have been supported militarily by Iran but do not have their own air force. But after 51 days of bombing and the heavily-armed Houthis still securely ruling from Sana’a, the U.S. president called it off. 

Lessons for Trump’s national security team: Some members “underestimated a group known for its resilience”; the same “men also misjudged their boss’s tolerance for military conflict in the region,” the Times reports. 

The Houthis’ reax to Trump’s halt: “Yemen defeats America,” the group posted in a hashtag on social media.

And Stimson Center’s Emma Ashford: “Frankly, I want to again give credit where it is due: many other administrations would have just kept going rather than be perceived as weak (*cough Biden cough*). That this admin did the cost-benefit analysis and called it actually speaks well of them.”

Why bring it up: Trump is visiting the Middle East this week, with stops in Qatar, the UAE, and Saudi Arabia, the latter two of which tried and failed to bomb the Houthis into oblivion for several years beginning in 2015. The Saudis were reportedly keen on assisting the White House in bombing the Houthis, including sharing a list of high-value targets inside Yemen; the Emiratis, on the other hand, were more skeptical. But several other key figures in the White House, including the new Joint Chiefs Chairman Air Force Gen. Dan Caine, were similarly skeptical before Trump made his call. Continue reading at the Times (gift link), here. 

Read more: 

---

Welcome to this Tuesday edition of The D Brief, a newsletter dedicated to developments affecting the future of U.S. national security, brought to you by Ben Watson and Bradley Peniston. Share your tips and feedback here. And if you’re not already subscribed, you can do that here. On this day in 1998, India conducted its fourth and fifth nuclear weapons tests in just three days. The event was later turned into a Bollywood film, “Parmanu: The Story of Pokhran,” released in 2018. 

Around the Defense Department

Golden Dome push sets stage for telecom battle over spectrum access. The wildly ambitious missile-defense vision is turning up the heat on a long-running fight between the Pentagon and the telecommunications industry for control of certain radio frequencies. 

“That area of the spectrum is golden, and we need to protect it to maintain national security. And I use the word ‘golden’ specifically, because the only way we can achieve Golden Dome” is by using frequencies around 3 gigahertz, Katie Arrington, who is performing the duties of the Pentagon chief information officer, told lawmakers Thursday.

But those are also prime territory for 5G and 6G services, and telecom companies have spent widely to keep Congress from hiving them off for the Pentagon. There may yet be a spectrum-sharing technological solution—and for that, you should read Lauren C. Williams’ report.

Update: The U.S. military flew more than 30 flights to Guantanamo Bay at a cost of more than $20 million in the first two months of the Trump administration, Senator Elizabeth Warren, D-Massachusetts, revealed Monday after relaying statistics from the Pentagon’s Transportation Command, or TRANSCOM. 

Rewind: The Gitmo operations began after Trump ordered an expansion of the base in an escalation of U.S. efforts to deport immigrants, which he hoped would hold up to 30,000 of “the worst criminal illegal aliens threatening the American people.” Nearly 300 were at least temporarily held there in the weeks following his order. 

However, by March, only 40 immigrants were detained there, and all of them were flown back to the U.S. by March 13, as The Hill reported at the time. Why? At least in part, “The Trump administration also faced multiple legal challenges, including a case brought by the American Civil Liberties Union over the lack of legal access to migrants at the military installation.”

More Gitmo stats from TRANSCOM: 

• “USTRANSCOM conducted 31 military and contract airlift missions to the U.S. Naval Station Guantanamo Bay between January 20, 2025, and March 25, 2025. These missions transported 715 passengers and 1016.9 short tons of cargo.”
• “As of 08 April, USTRANSCOM has flown a total of 46 flights on military aircraft in support of migrant deportation flights. The flights total 802.5 hours at an average cost of $26,277 per flight hour.”
• Over just a couple of months, Atlas Air, Delta, Omni Air, United Airlines, and Sun Country made over $1.6 million just from flying to Guantanamo Bay to assist migrant operations.
• “In anticipation of U.S. presence and increased capacity at U.S. Naval Station Guantanamo Bay,” DoD has increased the number of flights to the Naval Station.

Sen. Warren’s reax: “Every American should be outraged by Donald Trump wasting military resources to pay for his political stunts that do not make us safer. U.S. servicemembers did not sign up for this abuse of power,” she said in a statement. 

Additional reading: 

Trump 2.0

Flat defense budget? Blame OMB Chief Russell Vought. The head of the White House Office of Management and Budget is the one who decided to keep the Defense Department’s proposed spending for 2026 no higher than the current year’s and to force Congress to add money from the one-off reconciliation bill—a move one GOP senator has called a “gimmick.”

As Elon Musk pulls back from his hack-and-slash efforts, Vought is becoming the standard-bearer for the fight to shrink federal spending. “We want to put them in trauma,” he said of federal workers in 2023. “When they wake up in the morning, we want them to not want to go to work because they are increasingly viewed as the villains. We want their funding to be shut down so that the EPA can’t do all of the rules against our energy industry because they have no bandwidth financially to do so.” The Wall Street Journal has more, here.

Additional reading: 

Around the world

Coming soon: More U.S.-Russia talks on the future of Ukraine. The two nations’ envoys are set to meet Thursday in Istanbul ahead of possible high-level talks featuring the leaders of Ukraine and Russia, Reuters reported Tuesday. 

Ukraine’s president Zelenskyy said he’ll be in Istanbul if Russia’s Vladimir Putin goes. However, “President Putin, who has questioned Zelenskiy’s legitimacy, has not said whether he will take part,” and “a senior U.S. official said it was unclear whether anyone from the Russian government would show,” Reuters reports separately. The Associated Press has similar coverage. 

Extra reading: “New Small Russian Cruise Missile Captured By Ukrainian Intelligence,” The War Zone reported Monday. 

And lastly, a notable development: The Kurdish PKK in Turkey just disbanded, ending a 40-year Turkey insurgency, top officials announced Monday. 

The group’s Kurdish fighters played a key role in the U.S.-led war against ISIS across Syria, helping clear towns and villages of Islamic State terrorists as well as occupying select territory afterward, often co-located with U.S. forces in the region. But the PKK was also a terrorist group itself, carrying out attacks against Turkish officials going back to the 1980s. 

Big-picture impact: “Since the PKK launched its insurgency in 1984—originally with the aim of creating an independent Kurdish state—the conflict has killed more than 40,000 people, exerted a huge economic burden and fuelled social tensions,” Reuters reports. 

Ankara’s reax: “Our intelligence agency and other authorities will follow the upcoming process closely to avoid any road accidents and to ensure the promises made are kept,” President Tayyip Erdogan said Monday. 

Notable: “Kurds make up some 20% of Turkey’s 86 million population,” Reuters reports. Read more at AP or the BBC.

Defense One