After The Last King of Scotland picked up an Oscar in 2006 for Forest Whitaker's incredible performance as Idi Amin, its director, Scot Kevin Macdonald, has been struggling to find a rhythm in mainstream filmmaking.

Since then he's only directed 2009's State of Play and 2011's The Eagle, neither of which were more than average.

Can having one of the coolest and most impressive talents around - in the shape of Irish-raised (although born in New York) actress Saoirse Ronan - star in his latest film How I Live Now, strike a more positive note with audiences?

Elizabeth (Ronan) is a fine example of a troubled teen, but she does have her reasons; she's been sent by her dad in the USA to spend the summer with his sister Penn (Anna Chancellor) and her three children, Edmund (George MacKay), Isaac (Tom Holland) and Piper (Harley Bird).

As soon as she arrives she points out to 14-year-old Isaac (who has been sent to pick her up on his own in the Land Rover) that she doesn’t want to be referred to as Elizabeth, but Daisy. She also makes it perfectly clear that she has no intention of either having fun or being fun for her duration.

Back at the countryside retreat, she only has the briefest of chats with her Aunt, before she flies off to Geneva with work; she's a high profile analyst and is needed due the current political climate.

With her away, Daisy and her cousins are on their own until the au pair shows. But the au pair never arrives, as the country is suddenly the target of a nuclear attack. The youngsters soon find themselves having to deal with coping with war, on their own grassy door step.

When the Famous Five became four, they just didn't have their hearts in it anymore.

It's fair to say that Macdonald has a good eye for making the British countryside look pretty. What he lacks however, is the ability to create any sense of drama. The premise certainly doesn't help. Sure, the notion of a group of kids learning how to cope with a nuclear attack sounds like perfect fodder for a drama, but it's just not the case here. Instead Macdonald manages to make the outbreak of war nothing more than an inconvenience for a far too predictable love story to flourish between kissing cousins Daisy and Edmund.

Imagine 28 days Later without the zombies, and you pretty much have How I Live Now. The first half of the film sees Ronan moping like your clichéd teenager. The second half of the film sees her wandering around various foliage in the hopes of not being spotted by the military or locals. Her motivation is love, but the relationship takes off so quickly it's difficult to take Daisy all that seriously.

You'd also have to be concerned about her father's judgement; the film offers no news as to whether the USA is involved or not, so it looks that Daisy's dad has sent his daughter to a country on high terrorist alert for the summer, which doesn't seem that responsible. Mind you, she is an annoying teen.

If you accept the fact that the central relationship is a bit too flaky, the rest of the film's story soon comes tumbling down.

Macdonald gets some sweet performances from his young cast, but that's about it. His film lacks pace, drive and most importantly, a reason to watch it from beginning to end without going AWOL.