While Avangard, and Sarmat (especially Sarmat) render any anti-missile defense useless, Kinzhal and Zircon are the most impactful, because they change modern warfare radically and already made modern surface fleets obsolete even within non-nuclear paradigm. As I repeat ad nauseam about repeating this ad nauseam--this is a strategic catastrophe for NATO (and US) because everything what NATO's "fighting doctrine" was built around in the last 40-50 years has become simply useless.
[smoothiex12.blogspot.com]
This is what happens when DARPA research is outsourced to China and the other adversaries of the free world. Of course they're going to build the weapons we only played around with. The reason they got ahead of us is that we gave them our position to start from.