Before the start of business, Just Security provides a curated summary of up-to-the-minute developments at home and abroad. Here’s today’s news.

SYRIA

A US airstrike in northern Syria in March did in fact hit a building that was part of a “mosque complex,” a US Central Command investigation has found, contrary to the Pentagon’s adamant rejection of the idea that it had done so, causing civilian casualties in the process, in the immediate aftermath of the strike. Barbara Starr reports at CNN, citing two defense officials.

Syrian rebel delegates stormed out of cease-fire talks in Astana yesterday in protest of Russia’s plan for “de-escalation” zones in Syria as Russia, Turkey and Iran were invited to sign the agreement as guarantors, the BBC reports.

Rebels were concerned that the plan leaves too many loopholes for  the continuation of what they said was indiscriminate bombing on civilian areas by the Syrian military and some would not accept Iran as a guarantor, reiterating their demands for the removal of Iran-backed Hezbollah yesterday, Anne Barnard and Rick Gladstone write at the New York Times.

The de-escalation zones will be closed to US-coalition military aircraft, the Russian official who signed the agreement said today. The AP reports.

The US has “reasons to be cautious” about the plan’s chances of success but supports any effort to reduce violence in Syria, State Department spokesperson Heather Nauert said yesterday, the AP reporting.

Iran’s involvement as a “so-called guarantor” also concerns the US, Nauert said, adding that Iran’s activities in Syria have “contributed to the violence, not stopped it,” while its “unquestioning” support for President Bashar al-Assad has “perpetuated the misery of ordinary Syrians.” Nathan Hodge and Margaret Coker discuss the deal at the Wall Street Journal.

The plan was praised by the UN envoy to Syria yesterday as an “important, promising and positive step” toward the de-escalation of the conflict in Syria. [UN News Centre]

The de-escalation zones will be enforced from Saturday and will apply to both Assad and rebel forces in the checkpoint-demarcated areas, the checkpoints to be manned by the three guarantors Russia, Turkey and Iran “if necessary” but otherwise by unspecified “third parties,” explain Louisa Loveluck and Karen DeYoung at the Washington Post.

Putin is deploying units of Chechen and Ingush commandos to Syria, providing the Kremlin with its own elite ground personnel drawn from its Sunni Muslim population and placed across Syria, write Neil Hauer at Foreign Policy.

 The KOREAN PENINSULA

U.S. and South Korean agents are plotting to murder North Korean leader Kim Jong-un with a biochemical substance, North Korean state media alleges, vowing to “mercilessly destroy” the C.I.A. and South Korean intelligence agency agents it says have already entered the country. The BBC reports.

Legislation to impose new sanctions on North Korea targeting its shipping industry and individuals who employ North Korean slave labor abroad was voted in by the House 419-1 yesterday, Cristina Marcos reports at the Hill.

A “shadow security council” is being launched today by former military leaders and diplomats who were responsible for nuclear weapons to offer advice to global leaders on how to de-escalate what they say is the growing danger of nuclear conflict engendered by President Trump’s rhetoric and Russian President Vladimir Putin’s destabilizing moves, Bryan bender reports at POLITICO.

Philippine President Rodrigo Duterte called Chinese President Xi Jinping to discuss North Korea “at the behest” of President Trump, he said yesterday, Jake Maxwell Watts reporting at the Wall Street Journal.

South Korea’s hardline policy on North Korea will be exchanged for a more diplomatic approach if Democratic Party frontrunner Moon Jae-in wins the South Korean presidential election vote next Tuesday, writes Pamela Boykoff at CNN.

There are signs that President Trump’s “antagonistic” blustering rhetoric is working on China, with whom he might have opened the door to strategic cooperation on North Korea. Christopher Ruddy describes the view from China at the New York Times.

TRUMP ADMINISTRATION FOREIGN POLICY

Donald Trump will visit Saudi Arabia, Israel and the Vatican this month during his first trip abroad as president, ignoring the presidential tradition of visiting one of the U.S.’ immediate neighbors on his first foreign trip and instead sending what Carol E. Lee at the Wall Street Journal describes as a symbolic message of unification and common cause in the face of radical extremism.

Trump’s trip suggests that he is re-aligning the White House with Saudi Arabia and Israel’s anti-Iran position and is an indication that the president is falling back on the Bush-era reliance on Sunni Arab strongmen to control an agitated Middle East – and it’s a direct response to critics who call him anti-Islamic, writes Kimberly Dozier at The Daily Beast.

Secretary of State Rex Tillerson was less than clear on how much the US’ “fundamental values” of “freedom, human dignity, the way people are treated” will matter in the formulation of U.S. foreign policy in his speech to State Department employees Wednesday, observes the Washington Post editorial board.

“We have a fantastic relationship,” President Trump insisted after his one-to-one talks with Australian Prime Minister Malcolm Turnbull yesterday, telling reporters that reports that their January call was acrimonious were “fake news” and that in reality the call had been “very, very good.” Abby Phillip reports at the Washington Post.

The “Trump effect.” Trump’s impact on the domestic policies of other countries could undermine decades of U.S. foreign policy successes, writes Fareed Zakaria at the Washington Post.

Trump makes dictators stronger. Anne Applebaum describes how he does it at the Washington Post.

AFGHANISTAN

The “mother of all bombs” inflicted far less damage than first reported, according to a new investigation, raising the question of why the bomb – which the U.S. military said was a “very clear message to ISIS” that they would be “annihilated” – was dropped in the first place. Sune Engel Rasmussen reports at the Guardian.

Dropping the bomb was “the right employment” to “avoid the more extensive loss of life.” The head of U.S. Special Operations Command defended the decision to drop the GBU-43B Massive Ordinance Air Blast bomb on a tunnel complex used by Islamic State fighters in Afghanistan yesterday, Ellen Mitchell reporting at the Hill.

The Pentagon’s recommendations on troop numbers in Afghanistan will be sent to the White House within seven days, military leaders confirmed yesterday, acting assistant defense secretary for special operations Theresa Whelan saying that she expects the proposals will “recognize that Afghanistan is a very important partner for the United States in a very tricky region.” Ellen Mitchell reports at the Hill.

What will Trump do about the war in Afghanistan? The good news is that the president’s “counterinsurgency A-team” are able to influence the choices he makes, indications pointing to a preference on national security adviser H.R. McMaster’s part for a mini-surge in troops and greater resources as part of a sustained effort to weaken the Taliban just enough to allow for a peace settlement to be negotiated, but Trump will also face at least two major problems: he will need to convince Congress that Afghanistan is a credible partner, and he will need to communicate the plan in a way that doesn’t sound like nation-building. Michael Gerson writes at the Washington Post.

“Butcher of Kabul” Afghan militia leader Gulbuddin Hekmatyar made an impassioned plea for peace and unity in Afghanistan when he returned to Kabul, the city he once attacked mercilessly, yesterday, reports Pamela Constable at the Washington Post.

Afghan security forces killed a civilian and wounded 18 others when they fired without provocation on Pakistani census workers and the soldiers escorting them near the Afghan border, Pakistan’s army said today. Abdul Sattar and Munir Ahmed report at the AP.

IRAQ

U.S. combat troops will not remain in Iraq after the Islamic State has been defeated, Iraq’s Prime Minister said today following reported talks between Iraq and the U.S. on maintaining U.S. forces in Iraq. Qassim Abdul-Zahra reports at the AP.

US-led airstrikes continue. US and coalition forces carried out 28 airstrikes against Islamic State targets in Syria on May 3. Separately, partner forces conducted six strikes against targets in Iraq. [Central Command]

TRUMP-RUSSIA INVESTIGATION

The House Intelligence Committee held a closed-door briefing with FBI Director James Comey and N.S.A. head Adm. Michael Rogers as part of its investigation into Russian interference in the presidential election yesterday, committee members tight-lipped about the contents of the briefing afterward, reports Katie Bo Williams at the Hill.

Former acting attorney general Sally Yates could testify before the House Intelligence Committee within “weeks,” ranking member of the committee Rep. Adam Schiff (D-Calif.) said last night. Olivia Beavers reports at the Hill.

A revived section establishing a new committee to “counter active measures by the Russian Federation to exert covert influence over peoples and governments” was included in the intelligence community’s authorization bill, the final text of which was passed Wednesday evening, reports Jenna McLaughlin at Foreign Policy.

OTHER DEVELOPMENTS

Two Russian bombers and three other Russian aircraft flew across international airspace near Alaska Wednesday, the latest in a series of similar incidents, the U.S. sending two jet fighters to identify and intercept them, Gordon Lubold reports at the Wall Street Journal.

A periodic review guide to detainees remaining at Guantánamo Bay detention center as of May 4 is provided by the Miami Herald.

Relatives of some of the victims killed in the San Bernardino terrorist attack have sued Twitter, Google and Facebook for knowingly supporting the Islamic State, Doreen McCallister reports at NPR.

F.B.I. agents questioning suspected ringleader in the 2012 attack on a U.S. compound in Benghazi Ahmed Abu Khatallah aboard a Navy ship repeatedly refused his request to consult a lawyer, according to newly released court filings from his lawyers. Josh Gerstein reports at POLITICO.

A challenge to the U.K.’s director of public prosecution’s decision not to prosecute former MI6 officer Sir Mark Allen for his alleged role in the rendition and torture of Libyan dissidents Abdel Hakim Belhaj and his then-pregnant wife Fatima Boudchar may be held partly in secret, Owen Bowcott reports at the Guardian.