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

The US suspects ISIS of using chemical weapons against Kurdish forces in Iraq this week, officials said. It is suggested that ISIS may have obtained a mustard agent in Syria; this is the first indication that the group has chemical weapons at its disposal. [Wall Street Journal’s Adam Entous]

The Islamic State claimed responsibility for a bomb attack in Baghdad yesterday which killed at least 60 people. [New York Times’ Omar al-Jawoshy and Tim Arango]

Turkey and the US have taken preliminary steps to establish a “safe zone” in northern Syria though many details of the plan remain unclear, Turkish officials and Syrian rebel leaders have said. [New York Times’ Ben Hubbard]

Syrian Kurds, allied to the US, are confused by America’s growing allegiance to Turkey. [PBS’s Larisa Epatko] The Economist writes that “every day is carrying Turkey away from peace,” suggesting that de-escalation between the PKK and Turkey is still possible.

Australia may join airstrikes against ISIS in Syria, the country’s prime minister has said. [Al Jazeera]

ISIS is carrying out a greater number of attacks outside of Iraq and Syria. The Washington Post hosts visual graphics representing a year of attacks across the region.

US-led airstrikes continue. The US and coalition military forces conducted 12 airstrikes on Islamic State targets in Syria on August 12. Separately, military forces carried out a further 12 strikes on targets in Iraq. [Central Command]

Presidential candidate Jeb Bush defended former president George W. Bush’s Iraq War legacy in a speech on Tuesday night. [Politico’s Eli Stokols]

Three female ISIS defectors gave an interview with NBC News’ Richard Engel.

A visit by US ambassador to Syria Robert Ford to the uprising in city of Hama four months into the rebellion against the Assad regime was “the beginning of a string of US actions in Syria that were hastily planned, based on the incorrect assumption that Assad would soon fall,” writes Hannah Allam. [McClatchy DC]

“The Chilcot inquiry has arguably failed its remit, but its remit was probably not the one you think.” Gaby Hinsliff discusses the failure of the inquiry into Britain’s role in the Iraq War. [The Guardian]

“The road to Raqqa is the road from freedom’s burden.” Roger Cohen explores what drives thousands of young European Muslims to travel and join the Islamic State. [New York Times]

IRAN

Only one in three Americans approve of President Obama’s handling of the Iranian situation, according to a new Gallup poll released yesterday. [The Hill’s Jesse Byrnes]

Current and former Democrat members of the House Intelligence Committee wrote a letter urging their colleagues to support the nuclear accord, using past intelligence assessments to back their argument. [The Hill’s Julian Hattem]

If Congress votes down the Iran deal, Obama has “broad powers to act alone;” Michael Crowley explores what the president could do to “salvage” the deal at Politico.

Treasury Secretary Jacob J. Lew argues that rejecting the Iran deal “fl[ies] in the face of economic and diplomatic reality,” writing that after two years of negotiations with Iran, the international community does not believe increased sanctions will dissuade Iran from pursuing nuclear capabilities, in an op-ed for the New York Times.

Many of the critics’ arguments against the Iran deal are “irrelevant to the more urgent task of trying to prevent Iran from having nuclear weapons by 2017,” argues Harold Brown at the Washington Post.

GUANTÁNAMO BAY

The Justice Department is expected to either block or accept a habeas corpus petition to release a Guantánamo Bay prisoner before midnight today. Tariq Ba-Odah’s eight-year hunger strike has left him weighing just 74lbs; he was cleared for release five years ago. [Reuters]

The decision regarding the release of Ba-Odah will test President Obama’s resolve on the closure of the detention facility, suggests Murtaza Hussain. [The Intercept]

The Defense Department is blocking the transfer of three longtime Guantánamo Bay detainees for whom diplomatic deals to transfer home have been completed by the State Department, including UK permanent resident Shaker Aamer. [The Guardian’s Spencer Ackerman]

OTHER DEVELOPMENTS

Al-Qaeda’s leader pledged allegiance to the new leader of the Taliban, breaking a year’s silence. Ayman al-Zawahri’s message made no mention of the two year delay in announcing Mullah Omar’s death. [New York Times’ Rod Nordland]

A different group initially abducted a Croatian national believed to have been beheaded by the Islamic State’s affiliate in Egypt, according to the Croation foreign minister. [New York Times’ Joseph Orovic]

New guidelines tightening the programs that distribute the Pentagon’s unused gear and weapons to local law enforcement agencies will soon come into effect, one year after the military response in Ferguson, Mo. [Washington Post’s Dan Lamothe]

UN Secretary General Ban Ki-moon held a video conference with the heads of UN peacekeeping operations, Force Commanders, and Police Commissioners in the wake of revelations concerning sexual abuse by UN peacekeepers in the field, including Central African Republic. [UN News Centre]

The Pentagon is concerned that it is not prepared for a sustained military campaign against Russia, defense officials told The Daily Beast, reports Nancy A. Youssef.

Defense Secretary Ash Carter’s team of chiefs is coming together, however with President Obama soon leaving office, “they don’t have much time to accomplish several ambitious projects,” reports Marcus Weisgerber. [Defense One]