We end Act 1 with a clear understanding that it is actually too late for Ned to pull out, even if he wanted to: the weapon has been designed. If he were concerned about the military technology, he should really have worried about that before he took on the job. But he does not, at the end of Act 1, want to pull out. He clearly wants to see the project through. Materialising this idea is what he lives for, and he says this is at the cutting edge, this is where technology is. These ideas are going to have wider ramifications. And you begin to recognise him as seeing the whole thing as an experiment that will advance technology in general, the cutting edge. He is obviously getting his gratification or part of his gratification from the thought that he is contributing to technological progress. Or, perhaps, it's simply that he wants to be sure his theoretical design and, hence, his idea, can be proved in some sense correct. In other words, he wants to know that he is right.
If Ned is actually finding himself totally identified with the project, that the project and he are inseparable, he has been given an identity that he will struggle to relinquish. Yet, at the end of the Act, he is discovering that perhaps he should be having some doubts, and perhaps there is something that later he is going to have to contest. But you may agree that, if he so firmly identifies himself with his idea, the weapon being a manifestation of his idea, then that is going to be really rather difficult to give up. We all find it difficult to give up things that we value because they do tend to become a part of us. It is very difficult, perhaps impossible, to give up things as well as other people we value.