How are you going to shoot down an ICBM in the boost phase, if the satellite to do so is not almost directly overhead?
And BTW, are you aware that is only a period of 3 to 5 minutes? How are you even going to detect it, do the checks to ensure it is an actual ICBM and not just a test launch, accident, or something else? And then somehow magically get the authorization to fire the shot, and actually make it (with time to intercept)? But somehow, you think that can all be done in 3 to 5 minutes. Because trust me, nobody is going to authorize a weapon launch of any kind over a missile that is still over foreign airspace. That kind of order would have to come from the President, and it would be impossible to get that authorization in time.
No, I am discussing facts. I know you do not need to be overhead to detect it, but which are you talking about? Because you were talking about shooting one down, not detecting it. But guess what, you are still not going to see it launch from over the horizon. Period, there is this thing called the Earth in the way, until it gains enough altitude to no longer be obscured by the planet. Or are you a flat earther, that thinks there is no horizon?
This is why all intercept systems use the mid-course correction phase or the terminal phase to do their interception. To be absolutely honest, there is absolutely no way to catch a missile at launch. And when you talk about "boost phase", that is exactly what you are saying.
Remember that? That is where your claims jumped completely off the rails, and you have been spinning in circles ever since, apparently not able to keep observation and tracking with interception. You say A, I respond to that, then you spin on to B. I go back to A, and you return to B all over again.
You do not even know the terminology, you can not keep track of what part of flight is being discussed, or much of anything else. Even the SDI program of the 1980's was never intended to shoot them in the "booster phase" as you call it, it was always to target later when it was in freefall during it's travel and before it entered the terminal phase.
And please tell me, how do I think "theee dimensionally"?