In practice, nothing (against multiple multi-warhead ICBMs). If your foe only has one or two ICBMs maybe you have even odds. Against any nuclear-armed nation ot

In practice, nothing (against multiple multi-warhead ICBMs). If your foe only has one or two ICBMs maybe you have even odds. Against any nuclear-armed nation other than present-day North Korea, nothing. Even if you could intercept 90% of missiles/warheads if the opponent fires 20 (or 2000), you're screwed. There are multiple stages of flight in which one can attempt interception, but only the final stage after separation of warheads is realistic (which multiples the number of projectiles to intercept greatly): you can't intercept at accent unless you're very close to the launch site, hitting stuff in space with directed energy is defeated by a simple mirror, and hitting it with an inceptor is not feasible. An article I picked at random: https://breakingdefense.com/2022/02/no-us-missile-defense-system-proven-capable-against-realistic-icbm-threats-study/ https://breakingdefense.com/2022/02/no-us-missile-defense-sy...