I don't have planet busters until my scientists invent Orbital Spaceflight, and then that gets me these wonderful weapons deliverable only by rockets, never by needlejet or any other technology. And likewise, I don't have any other space tech until I have these rockets. Rockets are the key. You can't have planet busters or spaceflight without them.
And trust me, no matter how hard you try to get along, there's always some pro-war nutcase who wants a vendetta. You must arm. That doesn't mean you have to nuke anyone, but you damn well better at least be trying to get the technology. He is so right about the evil genocidal leaders. Stuff just doesn't ever get done without these kind of people.
One thing I was shocked to see Stephenson miss, though, is that you also need Pre-Sentient Algorithms. Orbital Spaceflight can't exist without it; it's a path dependency. (This is why, in the pseudo-reality (Earth simulations often played on the computers at the University) outside the true reality of SMACX, computer Science basically starts in the 1940s after you build something called Bletchley Park.) I cannot imagine how the author of Cryptonomicon, of all people, missed this.