Why doesnt Paul flee from his foxhole after he stabs the French soldier?

Paul stays where he is because there is machine gun fire all around.

"I can see him indistinctly. I have but one desire, to get away. If it is not soon it will be too light; it will be difficult enough now. Then as I try to raise up my head I see it is impossible already. The machine-gunfire so sweeps the ground that I should be shot through and through before I could make one jump."