Today's D Brief: 4th Sudan ceasefire begins; Evacs widen from outside Khartoum; Ukrainian weather forecast; Next Army chief; And a bit more.

The U.S. has begun evacuating private American citizens who want to leave war torn Sudan, White House National Security Advisor Jake Sullivan told reporters Monday in Washington. Some of those 16,000 citizens believed to still be in Sudan have already begun evacuating out of the coastal city of Port Sudan, to the northeast, as U.S. Navy ships in the region are rerouting for possible contingency use.

“We have deployed U.S. intelligence, surveillance, and reconnaissance assets to support land evacuation routes, which Americans are using,” Sullivan said Monday. “Once at the Port then, we are using diplomatic facilities in neighboring countries to help those Americans with their onward travel so that they can get safely out of the country,” he said, and added, “We remain available to any American in Sudan who is looking for support and guidance from the U.S.” 

The Brits announced similar measures for departures via an airport just outside of Khartoum on Tuesday as well. “Flights will be open to those with British passports and priority will be given to family groups with children and/or the elderly or individuals with medical conditions,” the UK Defense Ministry said Tuesday, and stressed, “British nationals should not make their way to the airfield unless they are called.” 

Several nations are looking to capitalize on a 72-hour ceasefire announced Monday evening by U.S. State Secretary Antony Blinken. “To support a durable end to the fighting, the United States will coordinate with regional and international partners, and Sudanese civilian stakeholders, to assist in the creation of a committee to oversee the negotiation, conclusion, and implementation of a permanent cessation of hostilities and humanitarian arrangements in Sudan,” Blinken said in his statement. 

• The BBC notes this is the fourth ceasefire that’s been brokered between the two warring factions, which began fighting 10 days ago. 

Latest from the capital city: “Gunfire and fighter jets were heard in Khartoum on Tuesday morning despite the ceasefire, but fighting seemed to be relatively calmer than Monday,” CNN reported Tuesday. 

More than 450 people are believed to have been killed so far, according to Sudan’s health ministry. CBS News reported Tuesday “the actual number of dead is believed to be significantly higher.”

Get a better handle on two major supporters to both sides of the conflict—Egypt and the UAE—via an explainer published Sunday by the BBC. 

Additional reading: 

• “Sudan fighters seize disease lab in Khartoum posing ‘huge biological risk’, experts warn,” the Telegraph reported Tuesday; Reuters has similar coverage, here; 
• “2 Sudan generals are at war with each other. Here's what to know,” CBS News reported Tuesday for those just now catching up; 
• “A visual guide to how elite US military forces evacuated US Embassy in Sudan,” USA Today reported Monday with maps and graphics; 
• And don’t miss, “United States Says Wagner Has Quietly Picked Sides in Sudan,” via the New York Times, reporting Sunday. 

From Defense One

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DHS Is Trying to Predict How AI Will Be Used for Harm // Alexandra Kelley: The coming inclusion of AI in critical infrastructure will open new and ill-understood vulnerabilities, the agency's Science and Technology Directorate leader says.

Welcome to this Tuesday edition of The D Brief, brought to you by Ben Watson with Jennifer Hlad and Sam Skove. On this day in 1980, President Jimmy Carter announced a failed overnight attempt to free 52 U.S. hostages held in Iran. This mission, called Operation Eagle Claw, was plagued by a sand storm and ended in disaster when an American RH‑53D helicopter collided with a C-130 transport plane, killing eight U.S. troops in eastern Iran.  

Developing: Some Ukrainian troops have reportedly crossed the Dnipro River to set up positions along a critical bank in the southeast of the country, according to analysis from the Washington-based Institute for the Study of War. It’s unclear how many forces Ukraine is sending to this location, which appears to be a fairly dismal and swampy area with few to no usable roads.
An ongoing rainy season is expected to continue slowing most maneuvering by Ukrainian and Russian forces, according to retired U.S. meteorologist David Helms, writing on Twitter on Tuesday morning. Current and predicted rainfall remain “well above normal” for the region, Helms said. Even Estonian Defence Minister Hanno Pevkur chimed in on the conditions this week, saying on Sunday it “could be another month before we can talk about a real [Ukrainian] counteroffensive” to retake occupied territory.
See for yourself: Here are some allegedly recent attempts to maneuver tracked vehicles in the Donetsk region; here’s an image from the trenches (which calls to mind the dreaded “trench foot” condition for military field sanitation nerds). Helms shared several other examples of atrocious wet conditions in his thread, which you can review here. 

Shandong redux: The Chinese aircraft carrier that participated in aggressive military drills near Taiwan earlier this month was spotted about 120 nautical miles off the island’s southeast coast on Monday, Taiwanese officials said. Taiwan’s military said it was tracking the Shandong and other ships in the carrier group and “appropriately responding,” Reuters reported from Taipei.
If you’re wondering exactly what the Shandong has been up to since December 2022, you’re in luck: Geo-intelligence researcher Damien Symon has mapped the carrier’s movements and posted that map on Twitter.
Guatemala’s leader on Tuesday pledged his unconditional support for Taiwan during a visit to Taipei. “Guatemala is one of only 13 countries with official diplomatic ties with China-claimed Taiwan,” Reuters writes.
“I want everyone to trust that Guatemala will continue to be a solid diplomatic ally to the Republic of Taiwan and will continue to deepen cooperation in all areas," Guatemalan President Alejandro Giammattei said, speaking in Spanish.
Related reading/from the region: 

• “UK warns China secrecy over military expansion risks 'tragic miscalculation,’” Reuters reported Monday from London;
• And “Powerful Air Force gunships double up in the Philippines during Balikatan exercise,” Stars and Stripes dutifully reported Monday from Subic Bay.

And lastly today: The White House has chosen Gen. Randy George to be the next chief of staff of the Army. The nomination was sent to Congress on April 20, according to the congressional record. Gen. George has served as Vice Chief of Staff of the Army since August 5, 2022.
“Gen. George is honored to be considered and will wait for the results of the confirmation process before commenting on the nomination publicly,” said Lt. Col. Loni Ayers, an Army spokesperson.
If confirmed, he will replace Army Chief of Staff Gen. James McConville, who has been at the post since 2019. In a statement to Defense One, McConville said George is “combat-proven leader who’s the right person at the right time and if confirmed will guide our Army into the future.”