I don't know a thing about modern missiles. All i know the declaration of Putin that Russia now has these things in service has been cried out on several media outlets as a "game changer", "a new treat to peace" etc (paraphrasing here)
I can see the advantages of hypersonic missiles:
very fast attack times.
much les time to respond by any defenses.
immune ? to current active defense tech.
Are these things as scary as they are made out to be ? (just the concept of operational hypersonic missiles, lets not delve here into wether how much of what Putin tells is mere propaganda and/or scaremongering)
Thanks for any input.
"Hypersonics" are new black. And without context that word is just buzzword what means nothing.
For starters, hypersonic missiles were in use by very many counties for soon to be a century, all the way from V-2. All ICBMs are hypersonic, Iskander is hypersonic, many SAMs and some AAMs are hypersonic... Buzzword came mostly from deeper work on airbreathing hypersonic missiles, which became more common in recent years. A bit later glider vehicles of ICBMs were included here too. Both are not totally new tech, gliders for example were worked on in US like half century ago, just never were fielded.
In case of Russia both are in work. Airbreather as Zirkon (still in work) and glider vehicle as Avangard, which went into IOC in December. Both are really useful indeed but as always not as gamechangers as screamed. Well, kinda.
Zirkon will be much fasted than current gen russian AShMs, thus it will be much harder to intercept. But it's not like any ship now is totally protected from P-800 barrage but will be totally vulnerable to comparable Zirkon barrage. It will just increase Pk from, let's say, 0.7 to 0.95 for properly committed attack. Useful, but hardly gamechanger.
With Avangard it's even easier. Yes, maneuvering HGV (Hypersonic Glide Vehicle) is a much harder to intercept that conventional ICBM. But in current state of things it matters very little. Because protection from ICBMs is... Well, it's a farce. There is NOTHING that ANY country in the world can do against massed ICBM strike with current or near future tech. US can intercept with good luck like 40 ICBMs in boost approach stage with GBI and with great lack a few dozens more warheads on descend. Russia can protect Moscow and surrounding from relatively harsh strike from dozens to hundred descending targets. For other counties even that capability is not present.
So in the end, if one ICBM will fly - all of them will fly. And if all of them will fly - it won't matter if you will intercept 2-4% of whole warhead count or none at all.
So both of those types are good and useful. And as usual both were looked at from amateur and wrong side.