Did you get to see the 2024 film Civil War, with its dystopian depiction of a present day USA in the midst of a violent meltdown? What made it such an effective thriller was that it all seemed so frighteningly real. Although the two sides in that civil war were fictitious, it hit a raw nerve precisely because of the very obvious divides that scar modern day America.

But interestingly it was actually written and directed by a British film-maker, Alex Garland, and he expressed worries about his home country, as well as the US. In both countries, he told the Guardian, "there's a lot to be very concerned about". He's not alone.

If you are an avid user of social media, you could almost believe that we are a nation disunited enough to have a full-on civil war of our own. And even away from the exaggerated adversarialism online, there are plenty of people worried that Britain is gripped by uncontrollable rage. It's a sense of discord that Britain's new prime minister, Andy Burnham, seems to recognise.

Since announcing his run for the Makerfield seat in May, he's repeatedly urged Britons to forget about party labels or factional identities and instead unite around pride in their local area. "Place first, not party first", is how he puts it. And as he entered Downing Street on Monday, he called for a "new national sense of unity, of common purpose and positivity".

But it's worth asking: just how divided really is Britain? Common Ground Evan Davis travels across the UK exploring the forces that are driving the UK apart, and he hears ideas to improve our sense of "social cohesion". Listen Now Some talk as though the population is ready to wield the pitchforks; that we are close to social breakdown; that a small spark could lead to a serious fire.

Last year, a commission co-chaired by the former Home Secretary, Sir Sajid Javid, warned in a report: "The bonds that hold society together - civic participation, and a shared sense of belonging - are under growing pressure." Well, I have just had the privilege of spending a month journeying - literally and figuratively - through some of the divisions that define modern Britain, for a Radio 4 series. Is there any common ground left in the country that Burnham has now inherited - or are we polarised to the point of no-repair? A defining split For a long time, Britain had a clear, defining split: social class.

What kind of job you had, how you spoke, what time you had your evening meal, what you watched on TV, how you voted… it was all pre-determined by your working or middle class background. Today, that has got a lot more complicated with a decline in the number of jobs that would have been regarded as "working class", and a big rise in the number of young people going to university from those backgrounds. That's not to say it isn't still there.

But probably the most obvious faultline in Britain and other western countries now is in values, with a marked difference between two sides: progressives on one side, and social conservatives on the other. If we have a civil war any time soon, it'll be the Allied Readers of the Guardian versus the United League of GB News Viewers.