Morning mail: US wavers on Syria air strikes Friday: James Mattis and Donald Trump tone down rhetoric on military engagement. Plus: no protection plan in place for 'punk turtle' US defence secretary James Mattis testifies before the House armed services committee on Thursday. Photograph: Chip Somodevilla/Getty Images Eleanor Ainge Roy @EleanorAingeRoy Good morning, this is Eleanor Ainge Roy bringing you the main stories and must-reads on Friday 13 April. Top stories Washington is still looking for evidence on who carried out Saturday's chemical weapons attack in Damascus, the US defence secretary, James Mattis, has said. Echoing a morning tweet by Donald Trump that appeared to walk back his threat of imminent action 24 hours earlier, Mattis said his main concern about a military response was how to stop it "escalating out of control". But the French president, Emmanuel Macron, said on Thurday his government had "proof" that the government of Bashar al-Assad was responsible for the attack. NBC and CNN quoted US officials as saying US intelligence also had evidence pointing to the regime's culpability. Analysts said the more measured tone suggested the US and allies were prepared to take longer to prepare a more comprehensive, multi-phase attack. At the UN, the Russian envoy, Vassily Nebenzia, said Russia's "immediate priority is to avert the danger of war". Asked if he was referring to a war between the United States and Russia, Nebenzia told reporters: "We cannot exclude any possibilities unfortunately because we saw messages that are coming from Washington. They were very bellicose." The Australian government has no plan to save an endangered Australian turtle species that received global attention on Thursday for its green mohawk and its unique ability to breathe through its genitals. The Mary river turtle, found only in that one river in Queensland, attracted worldwide headlines as one of the standout species on a new list of the most vulnerable reptile species compiled by the Zoological Society of London. But there is no national recovery plan to protect it from extinction and it is unclear whether any federal funds have been allocated for its protection. The international chemical weapons watchdog has backed the UK's findings on the identity of the chemical used to poison the former Russian spy Sergei Skripal and his daughter Yulia. The findings by the Organisation for the Prohibition of Chemical Weapons will be a relief to the UK government, which has said novichok, a military-grade nerve agent developed by Russia, was used in the attack. The UK foreign minister, Boris Johnson, said in a statement: "There can be no doubt what was used and there remains no alternative explanation about who was responsible – only Russia has the means, motive and record." The Australian government is pushing ahead with controversial legislation it says will create "back doors" into encrypted communication services – but still can't say when it will introduce the bill. After originally aiming to have the legislation before parliament in the first quarter of this year, the government has delayed its introduction. A spokesman for the acting attorney general, Marise Payne, said it was in "the advanced stages of development" and "the government is continuing to consult with key stakeholders". The former attorney general George Brandis first floated the idea last year, in response to law enforcement frustrations that encrypted communication services such as Whatsapp, Wickr, iMessage and Snapchat remained out of their reach. Tests on Captain Cook's sweet potato have shed light on how the crop reached Polynesia. Scientists say they have solved the longstanding puzzle, with their research proving the sweet potato evolved just once, probably in central or northern South America, and originated from a single ancestor. Analysis of part of a 250-year-old sweet potato plant collected during Cook's voyage to the South Pacific on HMS Endeavour suggests the species arrived in Polynesia by means of ocean currents. The findings cast further doubt on the idea that people in the Americas were in touch with Polynesians before Europeans arrived in the New World in the 15th century. Sport Where are the people at the empty Commonwealth Games? There are deserted streets, empty cafes and angry taxi drivers in the Gold Coast, as local businesses battle the unexpected downturn. A lot of the anger stems from an impression that Commonwealth Games organisers convinced some people to stay away. Kyron McMaster's 400m hurdles win gave the British Virgin Islands a first ever Commonwealth gold, and came months after his coach Xavier Samuels was killed in Hurricane Irma. Thinking time Is that really flu? Photograph: Tom Merton/Getty Images With the flu season almost upon us, doctors are already lining up stethoscope, thermometer and tongue depressor on their desks, says GP Elizabeth Oliver, to battle the wave of potential flu sufferers asking for antibiotics they don't need. "Influenza is that thing you had that time – if you could have made your brain work, you would have worried you were dying. Some of you cried. Some of you called an ambulance. You remember it forever and recount the tale at family get-togethers." Vaccination is no guarantee of prevention, but deciding whether to have one is a no-brainer, Oliver says. "Last year at least 3,000 Australians died of influenza, including healthy young adults and children." A Quiet Place has became a cause célèbre for anti-popcorn crusaders, with purists wanting to enjoy the Emily Blunt film in silence – but it's not the only part of cinema etiquette that could do with a 21st-century update. "Cinemas have long been considered safe havens where patrons can joyously munch on popcorn, sweets, pretzels and crisps," writes Joe Queenan. "A Quiet Place aficionados want to change all that, reversing more than a century of socially acceptable antisocial behaviour in the cinema." A chef who butchered a deer leg in front of vegan protesters has vowed he won't change, saying he and colleagues sources animal products with care – but opponents argue there's no such thing as ethical meat. Is there any hope for common ground? "I dreamed my whole life of opening Antler and it exists today as a small, local restaurant specialising in regional Canadian cuisine," he said, a few days after another protest outside the restaurant. "A group of protesters threatened that business, and my response, like any other business owner, was to defend it." What's he done now? Last week Trump described Robert Mueller's investigation of the Trump campaign's ties with Russia as a "witch hunt". But this week he's co-operating with him – at least according to his overnight tweet. "I have agreed with the historically cooperative, disciplined approach that we have engaged in with Robert Mueller (Unlike the Clintons!). I have full confidence in Ty Cobb, my Special Counsel, and have been fully advised throughout each phase of this process." Media roundup The NT News devotes its front page to asking the prime minister "What about us?" accusing Malcolm Turnbull of spending big in the southern states and short-changing the territory. "Malcolm Turnbull needs to stop treating Territorians like they are second-class citizens," chief minister Michael Gunner says. "If the federal government can afford to give Victoria $5bn to build a train line to the airport, they can afford to invest in the NT." The ABC has a feature on how to save Australia's farmland as the demand for affordable housing gobbles up more grazing land, which accounts for only 10% of the Australian landmass. And the Daily Telegraph reports that children as young as nine will begin taking lessons on consent as part of the NSW school curriculum. Coming up State and territory health ministers meet in Sydney today to discuss hospital funding and a looming doctor shortage due to visa rule changes. The federal electoral boundaries commission is due to rule on which federal seat in Adelaide will undergo redistribution. Supporting the Guardian We'd like to acknowledge our generous supporters who enable us to keep reporting on the critical stories. If you value what we do and would like to help, please make a contribution or become a supporter today. Thank you. 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