Good morning, I’m Tim Walker with today’s essential stories.

Trump sends bizarre, threatening letter to Turkish president

Donald Trump’s chaotic foreign policy has been further exposed by the emergence of a bizarre letter he sent to Recep Tayyip Erdoğan, warning the Turkish president “don’t be a tough guy” as Turkish forces launched their offensive in northern Syria. On Wednesday, Democrats walked out of a White House meeting after clashing with Trump on the issue of Syria. Senator Chuck Schumer said Trump had called the House speaker, Nancy Pelosi, a “third-rate politician”. Pelosi described Trump’s outburst as a “serious meltdown”.

‘Strategically brilliant’? Trump has insisted his controversial decision to withdraw US troops from north-eastern Syria was in fact “strategically brilliant”, claiming the Kurds he abandoned were “much safer now”, and adding that they were, after all, “no angels”.

Pompeo ‘ignored’ pleas to support Ukraine ambassador

Pompeo and the vice-president, Mike Pence, board separate planes on their way to Turkey on Wednesday. Photograph: Jacquelyn Martin/AP

The secretary of state, Mike Pompeo, ignored pleas to support the former US ambassador to Ukraine before she was ousted by the White House, apparently for political reasons, according to one of Pompeo’s former senior advisers. Michael McKinley testified as part of the congressional impeachment hearings on Wednesday, reportedly saying he had asked Pompeo several times to speak up for the ambassador Marie Yovanovitch, but that his appeals were “greeted with silence” – prompting him finally to resign last week.

Rudy Giuliani. Yovanovitch was pulled from her post in May, apparently at the urging of Rudy Giuliani. On Wednesday, a 44-year-old man turned himself in to authorities over allegations he conspired with several others, including a Ukrainian-born associate of Giuliani’s, to make illegal political contributions.

Ambivalence in Bolivia as Morales seeks a fourth term

Morales with supporters at a recent campaign rally. Photograph: Martin Alipaz/EPA

Bolivia is preparing to go to the polls on 20 October, with President Evo Morales seeking a fourth term after 13 years in power. His socialist government has maintained its popularity by investing the profits from a commodity boom into infrastructure and social programmes. But some are ambivalent about his continued rule, given the country’s history of authoritarianism, as Linda Farthing reports from La Paz.

Wildfire response. Until recently Morales’s re-election was considered all but inevitable, but the recent devastating Amazon wildfires – and in particular his government’s slow response – have slowed the president’s campaign momentum.

Rightwing groups pushing ban on campus criticism of Israel

The former Florida governor Jeb Bush speaks at the American Legislative Exchange Council’s annual meeting in 2013. Photograph: M Spencer Green/AP

Rightwing activists are pushing lawmakers in Republican-led states to outlaw antisemitism in public education. As the Guardian has learned, however, the proposed definition of antisemitism is so wide that it would prohibit debate about the human rights violations of the Israeli government – which, say first amendment advocates, potentially poses a threat to free speech on university campuses.

Smart Alec. The legislation is being pushed by an influential conservative network, the American Legislative Exchange Council, or Alec. Known as a “bill mill”, Alec specialises in propagating rightwing policy at state level through model bills.

Cheat sheet

Environmental groups have written to the banks linked to a forthcoming IPO of Saudi Aramco , the world’s largest oil producer, warning they risk financing the destruction of the planet with “the biggest single infusion of capital into the fossil fuel industry” since the 2015 Paris climate accord.

Street violence in Barcelona escalated in Wednesday on a third night of unrest in the Catalan city, with protesters setting cars alight and throwing acid at police amid demonstrations over the jailing of nine Catalan pro-independence leaders.

The web domain democracy.com is to go on sale next Friday in a sealed-bid auction, at which it is expected to fetch $300,000 or more. The coveted domain is currently administered by the veteran social activist Talmage Cooley.

Nasa is planning the first female-only spacewalk in the coming days – perhaps as early as Thursday – when astronauts Christina Koch and Jessica Meir are to replace a faulty battery charging unit on the outside of the International Space Station.

Must-reads

Comedian Ali Wong: ‘I was raised to be very open about my body.’ Photograph: Brian Bowen Smith/ABC via Getty Images

Ali Wong: ‘people should be too busy laughing to cringe’

In the past three years, Ali Wong has had two Netflix specials, co-written and starred in a romcom, and has now written a memoir aimed at her two young daughters. It has been a remarkable launch into the mainstream for a comic who started out with a foul mouth and filthy material. “I was very dirty back then,” she tells Emine Saner.

The search for Caravaggio’s saints

On the night of 17 October 1969, Caravaggio’s Nativity with St Francis and St Lawrence was cut from its frame above the altar at a church in Palermo, Sicily. Fifty years on, it is still one of the world’s most sought-after stolen artworks. And with suspects dying off, the search is now a race against time, as Lorenzo Tondo reports.

The rise of the city critic

We have long relied on the work of critics to inform and educate us about film, food and much else besides. Given the ever-increasing importance of cities to contemporary life, argues Colin Marshall, it is time city criticism was also recognised as a distinct category.

Uganda’s new birth control initiative: a soap opera

Uganda has one of the highest birth rates in the world. It also has some of the most dedicated soap opera watchers anywhere in Africa. Which explains a new plan to recut and overdub an existing Venezuelan telenovela to promote contraception and sexual health to a Ugandan audience. Amy Fallon reports from Kampala.

Opinion

Ilhan Omar has endorsed Bernie Sanders for president. AOC is planning to do the same this weekend, with Rashida Tlaib not far behind. Nobody should be surprised that the Squad is backing Bernie, says Arwa Mahdawi – like him, they are unashamedly progressive.

And yet the idea that female politicians would endorse an old white guy instead of Warren, an old white woman, seemed to throw a number of people for a loop.

Sport

The trolls who said Coco Gauff was a one-hit wonder after her remarkable run at Wimbledon have been proved wrong: the 15-year-old tennis sensation is here to stay, she tells Tumaini Carayol. “Ever since I was young my parents have always told me I could do it. So, a lot of the things that happened, yes, it’s surprising but it’s not as big a surprise as it appears to everyone else.”

The 27-year-old boxer Patrick Day has died as a result of head injuries sustained in his super-welterweight fight against fellow American Charles Conwell in Chicago on Saturday.