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.

IRAQ and SYRIA

Syria ceasefire. A new partial truce agreement has been arranged between the Syrian government and rebel forces in and around Aleppo, according to US, Russian and Syrian officials. The partial ceasefire comes following days of diplomacy by American and Russian envoys to stop the escalating violence there. [Wall Street Journal’s Felicia Schwartz and Raja Abdulrahim; New York Times’ Anne Barnard]  An “uneasy calm” has descended on Aleppo as the partial ceasefire comes into effect, some residents venturing onto the streets for the first time in days. [BBC] 

Hmeimim air base is still “humming” nearly two months after Russian President Vladimir Putin ordered a partial withdrawal of Russian air power from Syria. Andrew Roth reports. [Washington Post] 

An Army Officer is suing President Obama over the legality of the war against ISIS, testing Obama’s disputed claim that he does not need further legal authority from Congress to order the military to fight ISIS in Iraq and Syria. [New York Times’ Charlie Savage]

The Navy SEAL killed this week in Iraq died as he attempted to rescue Americans on a routine training mission, who become embroiled in an ISIS attack, according to US officials. [Wall Street Journal’s Gordon Lubold et al]  The death of Petty Officer First Class Charles Keating IV may portend the future of the US role in the war against ISIS, observe Mark Mazzetti and Helene Cooper. [New York Times]

Turkish forces again fired into ISIS-controlled territory in Syria today, in retaliation for rocket attacks that landed in a residential part of the town of Kilis, according to security sources. [Reuters; AP]

Routing ISIS from Ramadi came at a high cost, note Susannah George et al, reporting that destruction extends to “nearly every part” of the Iraqi city. [AP]

The “most dangerous” Australian Islamic State operative has been killed in a US airstrike in Mosul, Iraq, the Australian government has confirmed. Abu Khaled al-Cambodi, previously known as Neil Prakash, had been linked to various attack plans in Australia, and had encouraged individual attacks against the US. [AP]

US-led airstrikes continue. The US and coalition military forces carried out 22 strikes against Islamic State targets in Iraq on May 3. [Central Command]

“Poverty, desperation and the desire for revenge” have been cited as the driving factors pushing young Syrians to the Islamic State, in a new study by International Alert, a peace-building group. [The Guardian’s Ian Black]

OTHER DEVELOPMENTS

Israel has carried out airstrikes on Hamas targets in the Gaza Strip in retaliation for mortar rounds fired at Israel, its military has advised. [AP]

China and Russia have agreed to hold a joint anti-missile drill, to be held later this month at a Russian military research center, a Chinese state newspaper has reported. [Reuters’ Michael Martina]

Russia “cannot ignore any actions that may pose a direct or potential threat to its national interests,” Kremlin spokesperson Dmitry Peskov told journalists today. He insisted that a resurgent Russia does not pose a threat to anyone. [Reuters’ Dmitry Solovyov]

The US must take a more active role in Sudan, over 100 lawmakers have urged. Fighting between government forces and rebel groups, ongoing since 2003, has recently experienced a resurgence. [Wall Street Journal’s Felicia Schwartz]

It is not the right time to launch a Western military operation in Libya, Italy’s Defense Minister Roberta Pinotti told the Washington Post yesterday. Italy is a main proponent of the view that Libya’s unity government must strengthen domestic support, then request international assistance, before an allied operation could begin, reports Anthony Faiola.

The fact that Donald Trump will be able to receive classified US intelligence briefings once he is formally chosen as the GOP presidential nominee has “some spies sweating” over the possibility that he will inadvertently leak information during his, unrehearsed, improvisatory speeches, reports Shane Harris. [The Daily Beast]

What exactly is a UN sanction? The UN’s guide sets out “the what, who and how” of threatening, imposing and implementing sanctions, and eventually ending a sanctions regime.