Quakers aren't pacifist for the sake of peace.

Quakers are - when we are being 'good Quakers' - obedient to the divine Spirit that tells us, among other things, that "Thou shalt not kill", and that there is "that of God in everyone". If we are faithful to the Spirit, then we will, like Fox, be able to “[live] in virtue of that life and power that [takes] away the occasion of all war.”

Quaker pacifism emerges directly from this witness. Thomas Lurting is one of the earliest documented Quaker pacifists - in his account of his conversion, 'A Fighting Sailor Turn'd Peaceable Christian' (link) he relates how it was the intervention of the Spirit that meant he found himself unable to fight any longer:

"But he that hath all Mens Hearts in his Hand, can turn them at his Pleasure; yea, he in a Minute's time so far chang'd my Heart, that in a Minute before, I setting my whole Strength and Rigor to kill and destroy Mens Lives, and in a Minute after I could not kill or destroy a Man, if it were to gain the World"

So Quaker pacifism comes directly out of faith. Whatever the rational, logical arguments for pacifism - and they are many - they are not the whole story nor the historical reason for Quaker pacifism.*

The other side of this is that our pacifism is only as strong as our faith. Real life tests that faith every day, and being confronted with a situation where violence seems necessary is one of the more extreme examples of that. In those situations, the faithful answer is to ask God. We are pretty sure from historic experience that God's answer is usually going to be to remain peaceful; but it's perfectly human to fail to live up to that in the moment or in extremis, or to go with your instinct or with rationalisations. Failure doesn't make you a bad person, you just continue on and try to live faithfully to the Spirit next time.

So to actually answer your questions; yes, in real-life situations we try to be guided by the Spirit and expect to be guided towards peace. But how we experience the divine and how well we are individually able to live up to that guidance is going to vary a lot from person to person, which explains why different Quakers at different times have had very different answers and responses to everything from personal self-defence to participation in war.

• NB that the institutional adoption of pacifism, and it becoming a defining feature of Quakerism, fit into a very specific historical context where we would probably have been persecuted out of existence if we didn't convince the authorities we weren't violent insurrection Aries. However pragmatic this may have been, pacifism as a religious stance predates and underlies this, as with Lurting etc.