A UN report confirmed that sarin had been used in the attack on a Damascus suburb on August 21st that killed almost 1,500 people. Although the report did not say who was responsible, the sarin had been deployed with an artillery rocket similar to a type used by the Syrian army. Ban Ki-moon, the UN secretary-general, called it a war crime. Meanwhile, the diplomacy moved swiftly to back Russia’s plan for the Security Council to oversee the dismantling of Syria’s chemical weapons by mid-2014. America agreed, but said a missile strike on the Assad regime was still an option if it did not co-operate. See article

A former navy reservist shot dead 12 people at a naval facility in Washington, DC , before he was killed by police. In a depressingly familiar tragedy, Aaron Alexis had sought psychiatric treatment for mental illness. See article

A judge in New Orleans overturned the convictions of five former police officers for the Danziger Bridge shootings that took place in the aftermath of Hurricane Katrina, because of misconduct by prosecutors. The five had been convicted in 2011 for shooting six people, killing two, and for covering it up. But the prosecuting lawyers had prejudiced the case by posting comments about the five on the biggest news website in New Orleans, the judge decided this week. A new trial is to be held. See article

A showdown loomed between the White House and congressional Republicans over authorising spending to keep the government running until December. The Republicans’ condition for passing a spending bill is to “defund” Obamacare, which is a vivid red line for the president.

When to listen

Dilma Rousseff, Brazil’s president, called off a state visit to Washington due next month, following revelations that the United States National Security Agency (NSA) had monitored her e-mails and phone calls and spied on Petrobras, the national oil company. She failed to obtain from Barack Obama the apology and assurances she sought that the NSA would not continue to spy on her government. See article

Mexico was battered by simultaneous tropical storms on both its coasts, killing at least 80 people and destroying 35,000 homes. Acapulco, a resort that has waned in popularity because of violent crime, was badly hit, stranding thousands of tourists there. See article

Brazil’s supreme court voted six to five to hear appeals against their sentences by senior figures in the ruling Workers’ Party convicted of corruption. The appeal could mean they will not face jail.

Colombia’s former president, Álvaro Uribe, announced that he would run for the Senate in an election in March. Mr Uribe, who is barred from running again for the presidency, has become a bitter opponent of President Juan Manuel Santos’s effort to strike a peace deal with the FARC guerrillas.

Little indicators

Iran’s new president, Hassan Rohani, freed 11 prominent political prisoners and briefly unblocked access to Western social media. In a rare interview with American television Mr Rohani said Iran would never “seek weapons of mass destruction, including nuclear weapons” and that he had “full power and complete authority” to strike a nuclear deal. He is due to speak at the UN General Assembly in New York on September 24th. See article

Bahrain’s main opposition withdrew from talks with the government, following the arrest of a prominent dissident leader, Khalil Marzook, on terrorism charges.

The ruling party in Rwanda received three-quarters of the votes in parliamentary elections, giving it a majority big enough to change presidential term limits. That would allow Paul Kagame to extend his long rule. See article

A bit more exciting

In the week before Germany’s general election on September 22nd the centre-right and opposition centre-left parties were both polling around 44%. The leaders of the centre-right CDU and the centre-left SPD were said to be discreetly preparing for a “grand coalition” to form a government. See article

Unions in Poland staged the country’s largest protests in years, increasing the pressure on Donald Tusk, the prime minister, whose party was recently shaken by a bout of infighting and resignations that has left his coalition with a wafer-thin majority of just two in parliament. See article

A sympathiser of Golden Dawn, the Greek far-right party, was suspected of stabbing and killing Pavlos Fyssas, a hip-hop artist. While police raided Golden Dawn offices the party’s spokesman denied in parliament that Golden Dawn had anything to do with the killing. Lawmakers booed in derision and protesters took to the streets. See article

In a televised address, Silvio Berlusconi, the former Italian prime minister, vowed to stay at the centre of politics, despite his expected expulsion from parliament. But the media tycoon made no mention of previous threats to bring down the coalition government of Enrico Letta.

Religious hatred

A court in India ordered the arrest of 16 local politicians for inciting religious violence in the northern state of Uttar Pradesh. Over 40 people died in clashes between Hindus and Muslims around the town of Muzaffarnagar. See article

Abdul Quader Mollah, a senior member of Bangladesh’s largest Islamist party, was sentenced to death for war crimes committed during the 1971 war of independence. He had previously been sentenced to life in prison. See article

Australia’s new prime minister, Tony Abbott, brought his policy on those seeking asylum into force: those arriving in Australia by boat will now be towed to Indonesia. He has also promised to scrap a tax on carbon emissions introduced by the previous government.