What does Stanhope say the only thing a decent man can do?

Stanhope says that the only decent thing a man can do is "stand in".

If you went — and left Osborne and Trotter and Raleigh and all those men up there to do your work — could you ever look a man straight in the face again — in all your life? ( There is silence again.) You may be wounded. Then you can go home and feel proud — and if you’re killed you — you won’t have to stand this hell any more. I might have fired just now. If I had you would have been dead now. But you’re still alive — with a straight fighting chance of coming through. Take the chance, old chap, and stand in with Osborne and Trotter and Raleigh. Don’t you think it worth standing in with men like that ? — when you know they all feel like you do — in their hearts — and just go on sticking it because they know it’s — it’s the only thing a decent man can do. {Again there is silence .) Stand in, old chap — and do your share.