SAS importance in recent and past conflicts?

So basically – im behind (3 weeks on my history project) and need opinions and links to other sites that could help me with my question…
So, do you think the SAS have been very important in conflicts such as WW2, The Falklands, First Gulf War, War on Terror (Afghanistan) and the invasion of Iraq (2003 – I think?).
So if you come across anything to do with these – please send me the link but if you know anything then just post a comment! Thanks.