Former FR member ROTB would argue you have a responsibility NOT to fight. Unfortunately for ROTB, he/she got themselves banned.
From Rudyard Kipling, a year after the end of The Great War:
When the Cambrian measures were forming, They promised perpetual peace.
They swore, if we gave them our weapons, that the wars of the tribes would cease.
But when we disarmed They sold us and delivered us bound to our foe,
And the Gods of the Copybook Headings said: "Stick to the Devil you know."
"The streets are extended gutters and the gutters are full of blood and when the drains finally scab over, all the vermin will drown. The accumulated filth of all their sex and murder will foam up about their waists and all the whores and politicians will look up and shout "Save us!"... and I'll look down and whisper "No.""There really is nothing left to say to our enemies, is there?"They had a choice, all of them. They could have followed in the footsteps of good men like my father or President Truman. Decent men who believed in a day's work for a day's pay. Instead they followed the droppings of lechers and communists and didn't realize that the trail led over a precipice until it was too late. Don't tell me they didn't have a choice."
"Now the whole world stands on the brink, staring down into bloody Hell, all those liberals and intellectuals and smooth-talkers... and all of a sudden nobody can think of anything to say."
Rorschach – from The Watchmen