A decade on from the attacks of September 11, 2001, there is now a sizeable cinematic sub-genre dedicated to 9/11 and the subsequent military campaigns in Afghanistan and Iraq – the most notable perhaps being Kathryn Bigelow's 2010 Oscar-winning film The Hurt Locker.

There has also been a long-running TV show – Fox Network's 24 – which, although already filmed and about to air when the attacks took place, was prescient enough to have counter-terrorism as its theme and, over the course of its eight series, the paranoia of the Bush era as its background mood music.

The small screen has also been home to lesser-known serials such as HBO's Generation Kill, which follows a group of US marines through the 2003 invasion of Iraq and was co-written by The Wire's David Simon and Ed Burns.

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But it has taken a US remake of an Israeli series which had little to do with America, Iraq, Afghanistan or al-Qaeda to start asking bigger questions; ones which may give a little more perspective on the 21st century's tumultuous first decade. It asks questions about America's place in the world; about the moral relativism of the country's foreign policy; about loyalty, governance, faith (religious and otherwise) and, importantly, about patriotism.

The Israeli series was called Hatufim, or Prisoners Of War. Written by Gideon Raff, it dealt with the return to civilian life of two out of a group of three soldiers captured 17 years earlier during the First Intifada, in which Raff served as a conscript. Given the position the army and its soldiers hold in the national psyche, Hatufim proved highly controversial when it aired in Israel in 2008.

The American version is Homeland, adapted and developed by 24 writers Howard Gordon and Alex Gansa. It turns on the repatriation of Marine Sergeant Nicholas Brody (played by British actor Damian Lewis), who has been missing in action since 2003 and then is freed after a raid on a terrorist compound in Afghanistan. His nemesis – and, briefly, his lover – is brilliant-but-tortured CIA analyst Carrie Mathison (Claire Danes).

She is convinced that Brody is the "turned" American soldier an intelligence contact told her about years earlier, and that he's being lined up to commit a terrorist act on American soil. Everyone else – from Brody's family to Mathison's CIA bosses and their political masters in Washington, DC – believes he is an all-American hero with the best interests of the country at heart. In season one's dramatic finale, viewers learned that both things were true. Yes, it's a paradox, the writers seemed to be saying – get over it.

It is that subtlety which has helped give the show such purchase among critics and audiences on both sides of the Atlantic. True, it's another example of a drama which not that many people watch – only 1.7 million Americans tuned in for the series one finale, less than half the number of Britons who watched the episode when it aired here – but among its fans is President Barack Obama and it won a raft of awards this year, including six Emmys and two Golden Globes. For the Radio Times, who have Lewis and Danes on the cover of the current edition, Homeland is "officially the hottest US drama of the year".

Series two begins on Channel 4 tonight, just a week behind America. As an illustration of the writers' deftness and their desire to be as current as possible, the opening episode takes place against the background of an Israeli military strike against five Iranian nuclear reactors. It's an action many political commentators and Israel-watchers were anticipating ahead of the US presidential election, though it is now regarded as unlikely after last month's apparent climbdown by Israeli prime minister Benjamin Netanyahu.

In the world of Homeland, however, it has happened – and, in a ghastly echo of the fury over the recent short film Innocence Of Muslims, there are also violent protests outside US embassies across the Middle East. It's into this febrile climate that Mathison is called by her inscrutable former boss, David Estes.

She was last seen having electro-convulsive therapy for her bipolar disorder after being thrown out of the CIA. Now Estes needs her help because a previously dormant "asset" of hers has become active in Beirut and is demanding a meeting. Brody, meanwhile, has become a congressman and is being fêted by the vice-president as a potential running-mate in the next election.

Taking the role of Estes is another British actor, David Harewood. He explains the show's success simply: "I think audiences have been starved of quality political writing for a long time and Homeland has really hit the zeitgeist.

"With terrorism in the news and America itself beginning to question its role in the world after ten years of the so-called 'war on terror', and with the killing of Osama bin Laden, everybody asking themselves what the f*** has gone on for the last decade? Where are we? Are we any safer? Who's the enemy?

"And it's a really timely drama because it combines all those subjects with some really fantastic acting from Claire and Damian, wrapped in a love story, wrapped in a psychological thriller. It just hits all the buttons."

Creator Gideon Raff is involved with Homeland in an executive producer role, alongside Gordon and Gansa. Some who have seen both series think his Israeli original even more impressive than the remake, but Harewood's take on the differences between them sees him come down on the side of the American version.

"In Israel – and I think this is why Gideon Raff wrote the show – the state is very suspicious of returning prisoners of war. He was writing a soap about a guy who was coming back from being a prisoner of war who was being watched by the state and that was his dilemma. What they did here was flip that and make the state think Brody's a hero and make only one person – Carrie Mathison – think he's suspicious. I think that was a stroke of genius."

The other stroke of genius, he thinks, is the ability of the writers, whether by design or chance, to parlay current events and real-life situations into their drama. As an example, he recalls watching a television interview with one of the Navy Seals involved in the operation in which Osama bin Laden was killed. Under the pseudonym Mark Owen, the man published a controversial account of the event, a book titled No Easy Day, and then gave an exclusive interview to a current affairs TV programme.

Harewood says: "He was saying that on board one of the helicopters that flew into Pakistan was a female CIA agent who had been tracking bin Laden, and I just started thinking about Carrie Mathison. In the midst of all that [military action], there really was a brilliant, female CIA analyst on board. So it's extraordinary how close the scripts are to reality."

The issue of deadly strikes by unmanned US "drones" has also come under the spotlight. Their use has increased exponentially under Barack Obama (perhaps ironic, given how much he says he likes Homeland) and is so controversial in Pakistan that cricketer-turned-politician Imran Khan led a march last week protesting against their use. In season one of Homeland, a drone strike was used in a pivotal scene involving Brody; in season two, the extent of the CIA's involvement in that same attack is slowly revealed. Once again, big questions are being asked.

The third Brit in the Homeland cast, a new arrival for series two, is Rupert Friend. He plays CIA analyst Peter Quinn, who is brought in by Estes to oversee a special intelligence operation. He is also a man with secrets who is "not what he seems". Friend won't reveal more, except to say that based on what he's seen of the script so far – it is drip-fed to the actors, so they don't fully know how characters or storylines develop – it's "OK to be excited about season two".

Like Harewood, Friend puts the show's success down to the quality of the writing and characterisation. Unlike Harewood, he had the luxury of being able to watch series one as a punter. "I thought the first season was some of the best television I have seen," he says. "It doesn't patronise its audience with easy answers, schmaltz or repeated formulas. It feels more like a very well-crafted piece of cinema, delivered in segments."

But while Friend says the show isn't designed as propaganda – "It's storytelling. It's driven by its characters rather than to serve a moral message, which is I think why it's so gripping" – Harewood says there is no doubt that it is "liberal-leaning", a fact which has brought it some flak from the American Right.

"It's prepared to criticise America as well as promote it, which I think is one of the great things about it," Harewood says. "So the show definitely does get criticised and rightly so: it shows that the writers have their finger on a sensitive issue."

And it isn't only the American Right which has criticised Homeland. In that edition of the Radio Times which has Damian Lewis and Claire Danes on the cover, former Beirut hostage John McCarthy critiques the series and dismisses aspects of the plot as "ridiculous" and "an unrealistic portrayal of somebody re-entering society".

Given the nail-biting finale to the first series, we have to hope that McCarthy is right. But that won't stop millions of people tuning in tonight and for the next few months for another glimpse of what could happen if he isn't.

Homeland: Season 2 begins on

Channel 4 tonight at 9pm