I had delayed watching this movie because I knew it would be incredibly depressing - and it was. I really do not understand Irish history and probably never will. Civil wars in particular make my brain want to explode.
Set in 1920 Ireland, the movie tells of Damien O'Donovan (Cillian Murphy), a young doctor who has no intention of joining the rebellion against the British even after he sees British soldiers murdering a friend. Nonetheless, there comes a point when Damien can bear the British oppression no longer and so joins his older brother Teddy (Padraic Delaney) and the other rebels.
The Irish Republican Army wage guerrilla warfare against the British. After England and Ireland reach a peace agreement that will notionally allow Ireland to have some economic independence. Also, the country must remain part of the Commonwealth and loyal to the crown and as part of the treaty, Ireland is severed in two, with the north to remain part of England. Throughout history, colonial powers have a really bad habit of splitting countries into two and turning the peoples against one another :P
The movie shows how the battle turns from being a 'heroic' rebellion against a foreign occupier and becomes a civil war. Families are torn apart and the movie shows a literal story of brother against brother. Damien is among those who feel that the treaty has sold out the Irish people so refuses to give up their weapons.
The movie is beautifully acted, evocative and detailed. It's also incredibly depressing and miserable and I never, ever, ever want to watch it again. For me it reinforces how entirely baffling I find war in general - and civil wars in particular. Within a very short period of time, Damien and Teddy are turned against one another and friend is killing friend.
The other reason I hesitated before watching this movie is that part of me worried that it was going to be glorifying the IRA. Fortunately it was quite a balanced and accurate depiction of the organisation. I know that it's always a matter of opinion - freedom fighter, Fifth Column, hero - or terrorist? The British look truly evil in this movie, but what's more mindboggling and tragic is when Irishman kills Irishman. There's a bit where Damien says: "I hope that the Ireland that we're fighting for is worth this." It's a very telling moment.