On the road with The Killers: The return of America's greatest rock band

He doesn't drink, he's uncomfortable hanging out with the groupies, he's saddened by the moral crisis of the human race, and Mitt Romney sought his advice. Craig McLean meets the unlikely rock god Brandon Flowers.

The day ends around 1am, in a Viennese hotel bar, with Tom Jones, cradling a cigar and a brandy, asking Brandon Flowers when he last had a drink.

"Ah, four or five years," Flowers replies, in the slightly hesitant way he says many things. The Killers' frontman is jittering on the balls of his feet. He's patently uncomfortable amid the throng of musicians, backing singers and eager girls who have accompanied Jones from his hotel to the American band's digs, intent, it seems, on seeking out and hanging out with the Las Vegas foursome. Or, more accurately, with their singer. But Flowers is too old-fashioned polite to scarper to the safety of his room. So he stays and gamely tries to indulge in the boozy, wee-hours chit-chat.

Jones asks Flowers to explain his teetotalism. The veteran Welsh belter-turned-reality-TV-star is perhaps unaware of the Nevada native's Mormon faith. Flowers shoots a glance at me, and declines to answer Jones' question. "Uh, there's a writer here…" he demurs. "When did you last have a smoke?" one of Flowers' own people enquires. I don't hear the answer to that one.

Jones, 72 now, regales Flowers with tales of the 1960s. Of his high times performing in Vegas when the nickname Sin City still meant mobsters running the show rather than British royalty losing their shorts. The younger man listens intently. As is so often the case with the 31-year-old, one imagines he's conflicted at hearing such tales.

Flowers is a practising Mormon and happily married father-of-three, a decent, upright, moral fellow. But he's also a romantic, about his home town – the Killers named their second album Sam's Town after an old-timey casino located off Sunset Strip; Flowers opened Flamingo, his 2010 solo album, with a song titled "Welcome to Fabulous Las Vegas". And he's a romantic about the glorious ideal of America, and American rock'*'roll. In his slick, neat haircut and black leather jacket, he's Jimmy Dean fronting the E Street Band. Soon, though, we are talking in some detail about the cornerstones of Mormonism. I'm interested in the basic principles of the religion, particularly the idea that its founder, Joseph Smith, seemingly found a "lost" book of biblical scriptures buried in a hill in New York. How could that have happened? "It's a really cool story," begins Flowers, eyes shining.

he day began several hours previously, with a tour bus ride to an Austrian festival and the revelation that, in his declining years, late Libyan despot Muammar Gaddafi – ever a man keen to work that gadfly-dictator look – copied Brandon Flowers' image. Around the time of the Killers' chart-topping third album, 2008's Day & Age, Flowers took to wearing a jacket adorned with bespoke feathery epaulettes. They were made for him by Fee Doran, a British fashion designer. According to Flowers, she then had a call from Gaddafi's people. Could she make a similar outfit for the Brother Leader? A jacket with eagle-effect shoulders was apparently soon, ah, winging its way to North Africa.

The Killers are midway through a short run of European festival bookings, which included a headlining gig at the UK's V last month. The Frequency Festival takes place in St Poelten, in a gravelly car park by an exhibition centre an hour from the Austrian capital. As we drive to the site, Flowers gives me a tour of his living quarters. When you've sold 16 million albums, your band can afford a nice set of wheels. (In fact, the Killers have two such buses.) What, one wonders, is the best feature of this sleek charabanc? The full-size bed and sleeping area that are the special domain of Mr Flowers? Such spacious quarters must offer a welcome respite from the pokey bunks endured by the rest of the band.

"Uh, yeah, although…" Flowers starts falteringly. "I don't know if this is interview-worthy, but I sleep better in the bunk." He looks sheepish. "So I have this room but at some point every night, I wake up and go get in the bunk!"

For a performance-hungry zealot long accustomed to – or rather in love with – the rolling prison that is the life of a touring rock band, being on the road means sticking with the familiar, time-honoured claustrophobic comforts. So, the coffin-like bunk it is. "The womb," Flowers says, smiling and nodding. "Yeah."

But today there's something niggling at the perfectionist Brandon Flowers. A physical frailty that is undermining his usually healthy sense of rock-star self-possession. "Some people's are straight," he is telling me. "Yours is probably straight. But mine is curved a little. And eventually it just wore away…"

"They're talking about shoulders," says Ronnie Vannucci Jr, leaning into the tape recorder. This afternoon the Killers' easy-going, wise-cracking drummer has joined Flowers on interview duty. Good-natured but un-emotive bass player Mark Stoermer and permanently distracted guitarist Dave Keuning avoid publicity duties as often as possible. Their reasoning is sound: they're not very good at it.

"Ah-ha!" goes Flowers' embarrassed gurgle of a laugh at Vannucci's hint of innuendo. Then he explains more about his troublesome left shoulder, which has been bedevilled by a curved acromion. "It's pinched a nerve, and so they go in and they saw it straight – the doctor went in three different places, with a little camera and everything… And it's supposed to be cool. Anyway," he sighs, grimacing slightly. "It's worse now than it was before."

It's six weeks since Flowers underwent the surgery. But now the Killers have lurched from the last-minute, deadline-bucking completion of their fourth album, Battle Born, in New York into the critical pre-release promotional and touring period. The always-diligent, ambition-hungry frontman should have been up to rockin' speed by now. But he's still lame, on his upper-body left side at least. "I can't lift weights, and picking up the kids is hard," he complains. "Fist-pumping is hard!"

This is bad news indeed. The Killers are a band big on epic, roof-rattling songs, whether in the shape of the huge pop singalongs from their debut Hot Fuss (2004), or the starter-Springsteen belters from Sam's Town (2006). And after the synth-pop, Euro-friendly colours of Day & Age – then an ensuing hiatus in which three of the four members pursued solo projects – Battle Born is an album that seeks to yank the band back on track as America's greatest young(ish) rock outfit. So, Battle Born has a job to do. It has to out-anthem its predecessors. Yet here's their frontman with his anthemising abilities seriously under-powered. In every sense, he's pained.

"I had three cortisone shots before I had the surgery – didn't do shit for me!" Flowers gasp-laughs. "The third was the sorest, it was tightest – the doctor couldn't get into the groove between the bones, he was poking with the needle. Anyway," he says, smiling now, "I start to forget about it when we go on stage. But anything above my head with my hand, I feel."

This presents a particular issue with the band's comeback single "Runaways". If ever a song demanded two celebratory arms in the air, it's this rousing FM-radio scorcher about a "teenage rush", a "blue-eyed girl" and a boy who's "been on the trail for a little while". It's Kim Carnes' "Bette Davis Eyes" (which Flowers covered on his 2010 solo tour) retooled by the Boss via Bat Out of Hell. "Yeah," Flowers says ruefully. "I can only use the right arm."

So, his fist-pumping is compromised. What are we talking – eight out of 10?

"Seven," says Flowers, only half-joking.

The Killers, then, are back. Well, 70 per cent back.

Battle Born' is named after the motto of Nevada, which is itself a reference to the fact that the state was created in the aftermath of the American Civil War. The Killers formed, via newspaper ads and mutual acquaintances, in the state's biggest city a decade ago, and their success – instant in the UK, a little delayed in the US, worldwide courtesy of 2008 single "Human" – has bought them a studio in Las Vegas. It's called Battle Born, too. To Flowers, who writes all the lyrics, the phrase and what it stands for are important on multiple levels. It's a credo to live by, and it was a creative spur.

"I think of it as a call to arms. We have a lot of references like that [on the album]. It's like a positive kick in the ass. It's a wake-up call of sorts. Whenever I was struggling for anything lyrically, it helped just to go to that phrase. And it can apply to so much more than combat, and it's definitely the thread through this whole record.

"But there's always this other side to me," he adds. "It's not just the struggle. It's the 'what-are-we-gonna-do-to-fix-it? And to break through?'"

It's not only external struggles that exercise Flowers: he's not above addressing his internal dilemmas in his songs. Mormonism exalts the family and home life, frowns on alcohol, caffeine and nicotine, and certainly precludes drugs. There's not much there that the life of a rock band – and certainly not one as successful as the Killers – doesn't imperil. Flowers has admitted he's strayed from the faith's path in the past. His band's most famous chorus – "I've got soul but I'm not a soldier" (from "All These Things That I've Done") – references his battles with temptation.

Now "Runaways", a song about a lovestruck young couple, includes the line, "I got the tendency to slip k when the nights get wild." I ask him: is that storytelling, or is it autobiographical? (Bear in mind that Flowers has been with Tana, a former teacher, since the band's earliest days. They were married in Hawaii seven years ago; their three young sons were born in quick succession.)

"Ah-ha," comes that half-laugh, half-exhalation. "Ah, you know it's… there's a little bit of me in [everything] – it's inevitable that I'm gonna creep my way into these songs. But I am also good at observing what's happening around me. And 'Runaways', that's not some grand statement that I'm here to make. But it is an observation of what I'm seeing every day, and living. I see just…"

Flowers stops, frustration further stuttering his speech. "There just seems to be a tough… it's not the coolest subject, I guess… It seems to be harder than ever for people to commit to each other."

There, he said it.

"And it's… I guess it interests me. What's changed since my parents' generation?" wonders this youngest of six children. (Mormonism encourages large families.) "Or our grandparents'? Is it better? Or is it worse? I dunno."

I think it's safe to say that he does know. He thinks it's worse. He appeared to declare as much to the NME last month. "We don't seem to have it together as much as other generations," he said. When I bring up this quote in the back of the bus, he looks exasperated.

"Sometimes I make statements and I wish I could take them back. Cos do people wanna hear me talk about what I believe [about] the moral decline of the human race?"

"Yes," I reply, "they do."

"They wanna fuckin' hear that? Then I'm gonna sing 'Somebody Told Me' at V Fest?"

But much as he wants to use one of the Killers' frothiest, boppiest songs to dazzle and entertain the crowd at the UK's most corporate rock festival – which is the point he's making – Flowers can't hold back his true thoughts. Because immediately afterwards, he says, "You know, I think we're worse than we've ever been. Humans are worse than we've ever been. There's no dou– there can't be… we make Caligula look like… you know… it's just… whatev–"

Tongue-tied and furrow-browed, Flowers stops and regroups. "We're supposed to be talking about Battle Born," he states, discomfited.

But we are, already. It's an unashamedly commercial album, and its Flowers' emphatic, stirring stand against angst, aggro, chaos and the decline of Western civilisation. And he makes a great fist of it. Battle Born's wide, inclusive melodies are burnished with a golden optimism, and underpinned with an instinctive feel for the grand stadium moment on which the singer has long been focused.

Not shy about proclaiming his hunger for greatness for his band, Flowers wants to do what U2 do. Which is one of the reasons Daniel Lanois – producer of several of the Irishmen's albums – helped out with Battle Born. As did five other producers and mixers who, between them, have worked on big records by Bruce Springsteen, Bob Dylan, Madonna, Simple Minds, Arcade Fire and Depeche Mode. Rather than album-making by committee, Flowers sees it as cherry-picking. Similarly, he's intrigued by Coldplay's audience-adorning wristbands, the eureka moment that has helped the Brits turn every cold arena gig into an orgy of illuminated communion. For this keen student of rock history, there are lessons to be learnt everywhere.

With this kind of zeal, faith and straight-up-and-down musical electioneering, it's little wonder that Republican presidential hopeful Mitt Romney sought out an audience with the Killers' leader. "Yeah… it was a little, you know, I could kinda see that coming," says Flowers now of their lunchtime appointment last year at Las Vegas's Caesars Palace. "It wasn't too surprising."

What did Romney want from him? A way to reach the kids? "I think he probably sees a little bit of that in me," he laughs. "It's understandable. But we've [as a band] always been neutral, so we just kinda stay out of it. None of us is planning any rallies for anybody."

Did their shared Mormon faith mean Romney saw Flowers as a rock star he could trust? "Prob– Yeah, I'm sure. But I'm sure he's met with a few different people. But I think that's something that definitely made it a little bit easier to reach out to me."

What did he advise Romney on? "I didn't say anything. We didn't talk too much about that. The only person that's ever asked us if we had anything that we felt strongly about was [Democratic Senate Majority Leader and fellow Nevada Mormon] Harry Reid. To be honest I don't have… I just… My biggest issue is, I wish we took better care of our [war] veterans. I don't understand why we don't."

Would America benefit from a Mormon president? "Um. It wouldn't hurt… It wouldn't hurt any more than anybody else."

Anybody else of any other faith? "Yeah. There's no secret bombshell that's gonna get dropped if he becomes President! Some new law…"

…banning Coca-Cola, or any other supposed Mormon article of faith? Flowers laughs, just.

"That would be my biggest thing," he says eventually. "I don't think you shouldn't vote for him because of his religion. If you're gonna vote for somebody, you should learn about what their views are on things, and pick the guy that you identify with and believe in the most."

Backstage at Frequency, a few minutes before stage time, the Killers each do their own thing in their dressing-room. "We're four very distinct people," their singer had said, his voice rising to a laugh, as if he knew it was the understatement of the century.

Vannucci drums on the sofa. Keuning wonders whether his pink T-shirt – "It's salmon!" – looks cool and sorts out his Jägermeister cocktail. Stoermer drifts around wordlessly. Flowers, hair pompadoured just so, streaky-lean body poured into slim-fit black, drinks his regulation pre-gig Red Bull. Sometimes he goes for it and has two. "It makes me nervous," he says of the energy drink as he vibrates around the room, "which is good." He tries out some of the lessons his recently acquired singing teacher has taught him to make his voice "better, more powerful". He's working on his "head voice – it's like falsetto, but way cooler. Falsetto is what Chris Martin does."

At 8.48pm, the band hit the stage, and 40,000 Austrian fans go wild. "We are the Killers!" declares handsome Brandon Flowers in the wavery, Jimmy Stewart-under-water voice he uses on stage, "brought to you by way of fabulous Las Vegas, Nevada!" And with that, he blooms into charismatic life, lifting the curtain on an opening gig of a tour that will, more than likely, run for at least another year. It's a terrific show, and no one goes home undecided: the Killers are on the campaign trail once more, and the showman must go on. That dicky shoulder? If it was giving him gyp, Flowers hid it well.

'Battle Born' is released on 17 September. The first single from the album, 'Runaways', is out today (thekillersmusic.com). The Killers are playing London's Forum tomorrow, to be broadcast live on BBC Radio 1 and streamed on bbc.co.uk/radio1, and will appear at the Roundhouse, London NW1, as part of the iTunes Festival on Tuesday (roundhouse.org.uk)