For any fans of American cinema from the last forty years, there are three principle giants of the screen: Robert De Niro, Al Pacino and Jack Nicholson. These three, all emerging around the same time at the end of the Sixties and start of the Seventies, ushered in a new era of gritty, rough cinematic realism – albeit building on the work of the likes of Marlon Brando, James Dean and their fellow method actors from the Fifties. But unlike Brando and co they were given an added freedom by the concurrent rise of a new wave of experimental directors: the likes of Scorsese, Coppola, Forman, Kubrick, Friedkin – even Lucas and Spielberg – who were keen to try something new, and in the process shook Hollywood by its very foundations.

And yet despite their combined list of iconic movies stretching well into double figures –The Godfather (parts one and two), Easy Rider, Mean Streets, One Flew Over The Cuckoo’s Nest, Taxi Driver, Serpico, The Last Detail, Dog Day Afternoon, Raging Bull, The Shining, Scarface, Goodfellas and countless others – they’ve worked together surprisingly infrequently. Nicholson has appeared opposite De Niro on screen only once, in a small role in 1976’s The Last Tycoon, and has never acted alongside Pacino. De Niro and Pacino – despite both appearing in (and being Oscar-nominated for) The Godfather Part II in 1974 – have only ever faced each other on screen in 1995’s Heat, a film which owes much of its reputation as a modern classic to that long-anticipated standoff between two such massive cinematic icons.

Now, thirteen years after Heat, we may still not have the dream team-up of De Niro, Pacino and Nicholson all together in one movie, but De Niro and Pacino are at least playing opposite each other again – and that’s surely cause for celebration.

Well, yes and no. Because the trouble is that although both De Niro and Pacino were pretty much untouchable for much of the Seventies, Eighties and Nineties, in the last decade or so they’ve really not done a great deal of any note. Of course, it was always going to be hard to live up to expectations after so many genuinely astounding performances earlier on in their careers. But although De Niro’s evidently been having fun in the likes of Analyze This and Meet the Parents and their sequels, it’s hard not to see his over-the-top, pantomime-style work in the likes of The Adventures of Rocky and Bullwinkle and even the recent Stardust as being, well, a bit of a waste of one of the finest acting talents in cinematic history.

Pacino may have put in some decent performances in the likes of Insomnia and The Insider, but many of his other recent turns – such as in TV miniseries Angels in America, Ocean’s Thirteen and the 2004 version of The Merchant of Venice – have felt like he’s on autopilot.

So, will this finally be the revival of two of the powerhouses of modern film acting, or another passable disappointment? Will this story of two policemen trying to hunt down a killer who may be a cop provide De Niro and Pacino with enough meat for the sort of thing we always used to expect from them? Or is the De Niro / Pacino team up merely a marketing gimmick? And do we really care anyway? Because, let’s face it, De Niro on an off day and Pacino on autopilot are always going to be more interesting to watch than any number of bland identikit Hollywood teen heartthrobs. Even at their least inspired, they always manage to have flashes of brilliance. These two are icons for a reason.