Today's D Brief: Ukraine’s hypersonic claims; US boosts Gulf patrols; Border buildup; Dirty-bomb drug; And a bit more.

Ukraine’s air force says it shot down all six hypersonic missiles Russia launched overnight at cities like Kyiv. Ukraine’s air-defense systems allegedly shot down a dozen other missiles as well, including nine Kalibr cruise missiles, three S-400 Iskander ground-launched missiles, and about nine drones—including six believed to have been made by Iran—during a two-hour period beginning at around 2:30 a.m. local. 

Among the air-defense systems operating inside Ukraine: U.S.-made Hawk, Stinger, and Patriots; Germany’s IRIS-T; the jointly-developed NASAMS from Norway and the U.S.; and more like German-made Gepards. 

“Thank you to our Air Force service members and our partner states, who invested in securing the skies over Ukraine and all of Europe,” Ukrainian military chief Oleksii Reznikov tweeted Tuesday morning following the attacks. 

Russia’s military claims its hypersonic missiles struck one of the Patriot systems in the overnight strikes, according to Reuters. That’s disputed by Ukraine’s top uniformed official Valeriy Zaluzhnyi, who wrote on Telegram that all missiles were successfully intercepted. Russia also claimed all of its missiles hit their intended targets, despite apparent video evidence to the contrary, according to the BBC. (Moscow’s defense ministry separately claimed to have intercepted one of the UK’s newly-donated Storm Shadow cruise missiles on Monday; but there doesn’t appear to be any supporting evidence available for the claim just yet.)

By the way: There’s a hypersonic missile hearing on Capitol Hill today. The Pentagon’s top missile defense official Navy Vice Adm. Jon Hill is testifying before Senate appropriators this morning alongside Air Force Gen. Glen VanHerck, who is in charge of North American Aerospace Defense Command. Unlike most other appropriations hearings, this one is not being live-streamed for the public. Details, such as they are, here

See also: A scorecard listing all the (known) U.S. hypersonic tests, via Aviation Week. Find that here.

Update: The 31 Abrams tanks the U.S. military will teach Ukrainian soldiers to use “are intended specifically for training and don't necessarily have the capabilities that they would need to go into combat,” Defense Department spokesman Air Force Brig. Gen. Pat Ryder told reporters Monday at the Pentagon. Those M1 Abrams tanks arrived at Germany’s Grafenwoehr training area ahead of schedule last week, as the Associated Press first reported Thursday and we flagged on Friday. 

“The tanks that we will be providing to Ukraine are going through the refurbishment process right now,” Ryder added. But don’t expect them to arrive inside Ukraine for several more months, he said. “The M1 is a complex machine that requires a lot of maintenance to sustain it, [and] keep it operating. So that will be crucial, which is why we're doing the training in stride with the actual refurbishment,” said Ryder. 

Related reading:

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A ‘Stronger, Faster’ Intelligence Community Is Possible With AI // Lauren C. Williams: But caution is needed to make sure the technology doesn’t go off the rails.

Hypersonics, Nukes Top House Lawmaker’s Priorities List // Audrey Decker: But markups at Doug Lamborn’s HASC strategic forces panel are on hold amid threats to force a U.S. default.

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Welcome to this Tuesday edition of The D Brief, brought to you by Ben Watson with Bradley Peniston. On this day in 1966, the Chinese Communist Party began its violent “cultural revolution” with the so-called May 16 Notification

Nearly one-third of the troops ordered to the U.S.-Mexico border are in place, and the remaining 950 are expected in about three weeks, Pentagon spokesman Air Force Brig. Gen. Pat Ryder said Monday. Most of the service members are working out of El Paso, which is split by the scenic Franklin Mountain range, featuring extraordinary views of the region, including south into Mexico’s Ciudad Juárez. El Paso is also home to the Army’s First Armored Division at Fort Bliss. However, officials with U.S. Customs and Border Protection “ultimately will be the ones to determine [the troops’] disposition, since they're there to support CBP,” Ryder said.
Rewind: President Joe Biden ordered 1,500 troops to the border about 11 days ago, in anticipation of the end to public health restrictions known as Title 42 that had been in place since the pandemic. Those restrictions ended late last week as Republicans (like House Speaker Kevin McCarthy and Texas Gov. Greg Abbott, e.g.) and media outlets (like Axios and the New York Times) predicted “chaos” at the border once Title 42 was lifted on midnight Friday morning.
Even Biden expected calamity at the border when Title 42 expired, as he told reporters exactly one week ago. That chaos never materialized, however, and border crossings have in fact fallen since last week, the Associated Press reported Sunday. Even the Times described “a quieter than expected weekend in Texas, Arizona, California and nearby Mexican cities,” reporting Tuesday.
“Contrary to what was expected, migrants are not arriving en masse,” one pastor working in Ciudad Juárez told the Times.
“We have been planning for this transition for months and months,” Homeland Security Secretary Alejandro Mayorkas told CNN on Sunday. But he cautioned it’s still too early to declare anything like “crisis averted.” For example, there are still migrants reportedly headed north from Guatemala and Honduras—not that anyone expected those trends to drop off precipitously since the underlying economic and socio-political root causes of migration have not changed.
When reporters asked Biden how he felt things were going on Monday, he replied, “Much better than you all expected.” They then asked if he had plans to visit the border, and he answered, “No; it would just be disruptive, not anything else.” But, he added, “We have a lot more work to do. And we need some more help from the Congress as well in terms of funding and legislative changes.”
So what’s behind this at least temporary decline? It would seem to be most “Likely that smugglers are in ‘wait and see’ mode, as has happened in the past,” said Adam Isacson of the DC-based Washington Office on Latin America. Similar-looking declines happened in 2014 after Mexico changed its policies, 2017 after President Donald Trump was elected, and in mid-2020 shortly after Title 42 first went into effect.
Additional reading: 

China sees “a new genre of hybrid warfare” emerging from the Ukraine conflict. It combines "political warfare, financial warfare, technological warfare, cyber warfare, and cognitive warfare," writes Gen. Wang Haijiang, who leads the People's Liberation Army's Western Theatre Command.
Wang’s front-page article appeared Monday in Study Times, which the Washington-based Center for Strategic and International Studies describes as “a journal published by the Central Party School, focusing on authoritative analysis of Party directives, major theoretical and practical issues for cadres.”
"Various 'black swan' and 'grey rhinoceros' events may occur at any time, especially with the containing, encircling, decoupling, suppressing, and military threats of some Western nations," Wang continued, adding that China will seek new military advantages by building up capabilities in areas such as artificial intelligence, information networks, and aviation and space. Reuters has a bit more, here.
Today on the Hill: Pentagon chief Lloyd Austin will join State Secretary Antony Blinken and Commerce Secretary Gina Raimondo in a Senate Appropriations Committee hearing about “the Path Ahead for the U.S.-China Relationship.” That begins at 2 p.m. ET. Details and livestream, here

And lastly: A dirty-bomb antidote appears to be in the works. A new medication that might help people survive a dirty bomb—that is, an explosive that has been mixed with radioactive material—is being tested in the United States.
The 42-person trial is being run by SRI International, a non-profit research institute perhaps better known as the inventor of Apple’s Siri and other AI-type products. SRI is about 85% government-funded; this drug test is receiving funding from the National Institutes of Health, BBC reports
Know your munitions: With an effective radius measured in city blocks, a dirty bomb is not a nuclear bomb, nor even a weapon of mass destruction, according to the U.S. Nuclear Regulatory Commission, but a weapon of “mass disruption.”