Follow
Also as it comes to ITER specifically, it's an unique project with dozens of countries participating, and the objective being research rather than fast delivery of a working prototype. 90% of the delays in the project were specifically due to political & organisational issues rather than engineering or science.
There's a very good book I just found last year "ITER: The Giant Fusion Reactor: Bringing a Sun to Earth" by Michel Claessens, he writes about it in great detail.