Amazon.com: Tipping Point: The War with China - The First Salvo (Dan Lenson Novels)...

https://www.amazon.com/Tipping-Point-China-Lenson-Novels/dp/ [login to see]
There is a point brought up in this amazingly written book by David Poyer that I love asking people so I am putting it out to see the responses here. Also in light of the current world politics this is a very important question. A quote from the book in regards to BMD (Ballistic Missile Defense).

"I have heard the idea advanced that if we have technology to prevent a strike, we are bound by international law to stop it, irrespective of its origin."

This statement is basically saying that because we have the advanced technology to stop a Ballistic missile are we, or should we be, Obligated to stop it if we feel we can do so? On top of that should we stop attacks from any nation, regardless if they are our allies or our enemies, if they are not directly aimed at a military target and might cause civilian deaths?

This is in no way an attempt to cause a fight or an argument but simply to start conversation and debate into a very real possibility that we might be facing. The world is changing and this question might very well go from a fiction book into a very real news article. No opinion is wrong and every one's views do matter.