What your advocating ( limited missile defense )makes sense, in theory, but the problem with that is one of scale. If you can shoot down "tens of incoming missiles", then the next step would be to ramp it to being able to shoot down hundreds ( or thousands ). That's what is destabilizing about missile defense, not the rogue missile launch protection capability, but that possessing that capability against all missile launches. Unless the US were to share the technology with Russia and China( highly unlikely), it would render their arsenals impotent( or nearly so) and coupled with a US refusal to disavow a 'first-strike" option put them at high risk of being destroyed without an effective retaliatory capability. Long before that happened, you'd likely have a final showdown and curtain call. That is what makes missile defense "offensive" and highly dangerous. Agree on the rest.