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

Secretary of State John Kerry flew to Geneva today for further talks on a Syrian ceasefire with Russian Foreign Minister Sergei Lavrov, David Brunnstrom reports for Reuters. State Department officials have played down the prospect of a deal being reached today, but said steady progress was being made.

The US has sent 400 additional troops to bolster Iraqi forces preparing to retake the Islamic State-held city of Mosul, report Ben Kesling and Gordon Lubold at the Wall Street Journal.

Turkish airstrikes have destroyed four stationary targets in northern Syria today, reports Reuters.

More than 70 aid groups have suspended cooperation with the UN in Syria, demanding an immediate investigation into the UN’s operations in the country over concerns that President Assad has been manipulating the organization in order to deny aid to people in besieged areas, Emma Beals and Nick Hopkins report at the Guardian.

A senior commander of Syria’s rebranded al-Qaeda affiliate Jabhat al-Sham – formerly the Nusra front – has been killed in an airstrike in a rural area of Aleppo province, the group said yesterday. They did not say who carried out the airstrike, reports Reuters’ Suleiman Al-Khalidi.

US-led airstrikes continue. US and coalition forces carried out five airstrikes against Islamic State targets in Syria on September 7. Separately, partner forces conducted seven strikes against targets in Iraq. [Central Command

AFGHANISTAN

Afghan forces have successfully retaken most of the southern provincial capital Tirin Kot this morning after the Taliban almost overran it yesterday, a Kabul defense official has confirmed. [AP]

The Taliban were close to taking Tirin Kot yesterday, overrunning all security posts around the city and firing on the police headquarters and the governor’s compound. By afternoon, however, NATO airstrikes began targeting Taliban positions, and reinforcements had started to arrive from a neighboring province. [New York Times’ Taimoor Shah and Mujib Mashal]

Navy SEALs led an unsuccessful attempt to rescue a US and an Australian university professor from the Taliban last month at a compound in the mountains of eastern Afghanistan, US officials confirmed yesterday. The professors were taken at gunpoint on Aug. 7 from their vehicle in Kabul, report Matthew Rosenberg and Adam Goldman at the New York Times.

NORTH KOREA

North Korea successfully conducted its fifth underground nuclear test today, this time producing a more powerful explosive yield than ever before, according to South Korean officials. [New York Times’ Choe Sang-Hun and Jane Perlez]  Pyongyang confirmed this hours later. [The Guardian]

NATO Secretary General Jens Stoltenberg “strongly condemned” the test, telling North Korea to drop all nuclear and ballistic missile activities, which he said were “consistent provocations and violations” of UN Security Council resolutions. [Reuters]

Defense Secretary Ash Carter said he will stay in close contact with South Korea and other allies in the region following the test. [Reuters]

China will formally protest the test with Pyongyang’s ambassador in Beijing, spokesperson Hua Chunying said today, calling the test the latest act to destabilize relations on the Korean Peninsula. [AP]

North Korea’s growing nuclear arsenal presents a threat that the next US administration will have to prioritize and may mean that Washington will be forced to bargain with North Korea, suggests Julian Borger at the Guardian.

These missile launches are “adding up to something very troubling,” writes Anna Fifield at the Washington Post. Advances in North Korea’s missile program could enable it to outsmart missile defense systems, making the missiles more attractive to potential customers.

Why did North Korea wait till now to test this device, ready since May? Gordon G. Chang at The Daily Beast suggests that the Kim regime tested at this time because it realized China – more upset with Seoul’s plans to install a US THAAD missile defense system – would not impose costs for the detonation.

Notable developments in North Korea’s nuclear weapons and missile program this year have been provided by the AP.

GUANTANAMO BAY

President Obama is not ready to concede that Guantánamo Bay detention center will remain open after he leaves office, he said yesterday. Kathleen Hennessey reports for the AP.

“The United State is not, should not be the policeman for the world,” death penalty defender for accused terrorist Abd al Rashim al Nashiri, Richard Kammen, argued yesterday in the first hearing at Guantánamo Bay in the USS Cole attack case,  asking the judge once again to dismiss the part of the case involving al-Qaeda’s 2002 bombing of a French oil tanker. [Miami Herald’s Carol Rosenberg]

FRANCE

A French police officer was stabbed and a suspect was shot yesterday while detaining three women in connection with the terrorist investigation into a car containing gas cylinders found earlier this week close to the Notre Dame Cathedral in Paris, report Inti Landauro and Stacy Meichtry at the Wall Street Journal.

The women were planning an attack on Paris railway station the Gare de Lyon on Thursday, the French interior ministry has said today. Reuters’ Gérard Bon reports.

A total of seven individuals have now been detained in connection with the apparent plans for “imminent” violence, the AP’s Phillipe Sotto and Lori Hinnant report.

RUSSIA and UKRAINE

A “tenuous” ceasefire has held for a week along the front lines in eastern Ukraine after months of intense combat between Ukrainian soldiers and Russian-backed separatists, according to Ukrainian officials. [Wall Street Journal’s Nathan Hodge]

Ukraine cannot get back Crimea, even though Russia took it by annexation, Czech President Milos Zeman – who has often spoken out against EU sanctions against Russia – is reported to have said. [Reuters]

OTHER DEVELOPMENTS

America is spending on more missions to send more elite US forces to train alongside foreign forces in more countries around the world, according to documents obtained by The Intercept’s Nick Turse.

US airstrikes across Asia, Africa and the Middle East over the Labor Day weekend highlight the diffused terrorist threats that have persisted throughout President Obama’s tenure and are likely to continue under the next president, Missy Ryan writes at the Washington Post.

Israeli and Palestinian leaders have agreed in principle to meet in Moscow in an effort to relaunch peace talks two years after they last broke down, according to Russia’s foreign ministry. [Al Jazeera]

Iran has begun manufacturing rotor tubes for centrifuges, the spinning machines used to enrich uranium, the International Atomic Energy Agency has said in a review issued yesterday. Although Iran is allowed to make these parts, it is only allowed to do so under certain circumstances, reports George Jahn at the AP.

All parties in Yemen’s civil war must halt all military activity and abide by the terms of a Cessation of Hostilities agreed in April, the UN has said. [AP]

The Turkish military is conducting its largest ever operations against Kurdish PKK fighters in the southeast, President Erdoğan has said. [Al Jazeera]

Four British men have been charged with planning to carry out acts of terrorism almost two weeks aver they were arrested in a series of raids in Birmingham and nearby Stoke-on-Trent, Alexis Flynn reports at the Wall Street Journal.