That's far too simplistic for anyone to answer as it stands. My general response would be that if politicians start a war, they should f*cking well go and fight it themselves.

However, I don't think that the British in 1939, for instance, had much choice - it was defend their country, or be occupied by the Nazis. For that, I honour and respect those who fought for our freedom.

Being a newly qualified old geezer, hopefully I would be exempt.

But in principle I'd be willing to do my bit, depending on circumstances as Martin says.

I agree with you here John.  I most certainly couldn't fight the Iraq / Afghanistan wars, but the second world wars yes of course.  Is that because it was my homeland that was at risk? I think it was that and also the fact that the case for the Nazis to be stopped was so clear cut in my eyes. Whereas the Iraq / Afghanistan wars were heavily sold to us and it was evidently clear that the world was being manipulated to fit someone's agenda.
I have a few friends in the Royal Marines, they say that they rarely fight for the cause, they fight very much more for the fellow soldier beside them and together they advance watching each other's backs. 

If I could hand pick them myself, I'd be in 

I came close in the early 80's over the Falklands War. Maybe it was 'friends' trying to wind me up at the time, but it did give me the shivers for a while. I'm within a week of my 60th birthday now, and regarded as past it in any case in all sectors including some audio forums, so I'll just grab me zimmer frame and toddle off...

Like Mike I'm too old now, and like Dave I remember the Falklands "scare stories" about the reintroduction of conscription. In fact we had people (and I promise I'm not making this up) who would constantly jump off of desks, landing as hard as they could, in an attempt to get flat feet which they were convinced would get them deferred from the draft. Of course, it was myself and a couple of mates who had done the convincing but that's neither here nor there.
Yes, I'd have gone.  No, it wouldn't have been with a cheery smile.  If you're willing to fight for your country you need to trust in your country's ability to choose when and where that willingness is deployed, not suggest that whether you go or not is a personal choice.  If you've said you'd go but only if it suits you then you might as well say you wouldn't fight.  Once battle is joined you either fight or run away.  There is no middle ground.  

It'll be the Home Guard [Dads Army]

Check the context Chris. I was talking about the people who said they would fight, but only if the cause suited them.