>>903>for every hypersonic ICBM developed there are radars made of reflective material detecting and sending missiles towards it before it can hit its target.Problem N°1 anti missile defense systems don't work. The data about performance in real world condition (actual combat) suggests that they even struggle against low speed, low altitude, low range unguided missiles. Expect that the 50% interception rate from synthetic tests will drop dramatically in an actual conflict.
Problem N°2 If they worked you'd need too many.
If your opponent has one ICBM you need a missile shield for every potential target. The more ICBMs your opponent has the larger the list of potential targets gets.
Problem N°3 war-heads that can subdivide into many small bombs.
Nukes can be made very small, and you can fit potentially hundreds or thousands of small nukes on a single ICBM, at this point statistics of large numbers take over, and getting a high interception rate is very unlikely, even if you had tons of effective missile defenses. Decoys will make this even harder.
Problem N°4 newer intercontinental missile systems that are already in service are not flying on ballistic trajectories, and it's not realistic to think that those can be intercepted by another missile, because without a predictable predetermined flight path, it's not likely that you can catch up to something going above Mach 5.
Once you can make lasers or directed particle stream weapon of sufficient power, this will change and anti missile defenses will become plausible, but not before.