Donald Trump's decision to withdraw US forces from north-eastern Syria was heavily criticised by many in his own Republican party. It's argued that this will create an opening for Turkey to attack Kurdish fighters - who were vital to defeating Islamic State in Syria - on the border between the two countries.

The US president has responded with a series of angry tweets, promising to "destroy and obliterate" Turkey's economy if its military goes "off-limits". The Pentagon and the State Department, meanwhile, say there has been no major shift in US policy and that only a few of the 1,000 US troops in north-eastern Syria have been pulled back.

So what is going on? BBC diplomatic correspondent Jonathan Marcus describes the situation as an "object lesson in how dysfunctional US foreign policy-making has become".

We explain why Turkey is planning an assault on Kurdish fighters.

With 23 days to go until Brexit is due to happen, the Institute for Fiscal Studies is warning that leaving the EU without a deal would push UK debt to 90% of national income - its highest level since the 1960s. Borrowing would also be likely to rise to £100bn a year, the think tank adds. Here are the details.

But the Treasury says it is ensuring a "fiscal anchor" will be maintained and that "long-term stability" is key to its planning. BBC economics editor Faisal Islam gives his take on the IFS's forecasts.

Meanwhile, Scotland's Inner House of the Court of Session is to consider whether a court can, in effect, sign a letter to the EU requesting a Brexit extension. The court will also hear an appeal against a ruling, given on Monday, that Boris Johnson can be trusted to apply the law.

Extinction Rebellion (XR) protesters are expected to continue blockading sites around London, as well as many other major cities around the world. Almost 300 people have been arrested in the UK capital.

Speaking at a book launch on Monday night, Prime Minister Boris Johnson criticised those involved, calling them "nose-ringed climate change protesters" and "uncooperative crusties".

But XR supporters see things differently. "We're here because we want the world to still be alive when we die," said one of them, nine-year-old Rafi. We explain what XR is and what it wants.

Several papers lead on UK demands for the return of the wife of a US diplomat who is wanted by police over her alleged role in the death of teenager Harry Dunn in a road crash in Northamptonshire. The Daily Mail reports on his mother, Charlotte Charles, calling on Anne Sacoolas to come to the UK and face justice. But the i reports that diplomatic immunity, which Ms Sacoolas has, is rarely waived. Elsewhere, the Guardian leads on the Institute for Fiscal Studies' warning of a debt hike if the UK leaves the EU without a deal. And the Daily Telegraph says children's lives are being "wrecked by obsessions fuelled by technology".

From elsewhere