Some promising technologies that could mitigate the BM threat. No doubt technical challenges remain but at this point it would appear that the basic technology is understood and it's just a matter of harnessing the political will to realize them.
BPI to target BMs during ascent when they are most vulnerable. MOKV-tipped GBI and SM-3 to target incoming clusters of warheads and decoys during the mid-course phase and FEL and EMRGs for terminal BMD.
https://www.usni.org/magazines/proc...oost-phase-could-counter-north-korea-part-two
Research performed at the Massachusetts Institute of Technology was conducted to determine the feasibility of deploying a boost phase intercept (BPI) system on board a medium-to-large-sized UAV. The use of the remotely-piloted MQ-9 Reaper, the infrared Multi-Spectral Targeting System C (MTS-C) sensor, and a notional airborne hit-to-kill interceptor for conducting long-range intercepts of ballistic missiles was analyzed. These systems were selected because they had reached an adequate technology readiness level to create a BPI capability in the near- to mid-term. The MQ-9 Reaper has an extensive demonstrated operational capability in multiple theaters. A Missile Defense Agency test had already successfully integrated the MQ-9 and the MTS-C to successfully track a ballistic missile from boost into mid-course.
Pentagon Accelerates Work on Multi-Warhead Interceptor - Defense One
The Missile Defense Agency, or MDA, is accelerating the development of an interceptor that can take down several incoming warheads — or one warhead and several decoys — simultaneously. While MDA officials say the move is not a response to any specific threat, one prominent defense watcher notes that North Korea is likely working hard on missiles that can fire decoys to confuse interceptors...
The developed airborne BPI system engaged the threat missiles in a series of simulations. Two MQ-9 Reapers utilized notional MTS-C sensors to track the ballistic missiles in boost phase, with one aircraft launching the interceptor. Two aircraft were necessary, as the MTS-C is a passive sensor that requires triangulation to generate timely tracks. One aircraft remained stationary and only provided a second sensor for tracking, while the aircraft that launched the interceptor moved across a programmed grid in a series of engagements. Both aircraft maintained station sufficiently far from enemy territory to avoid notional antiair threats. The engagement simulation calculated the required performance of an interceptor launched from each location, considering the key performance metrics of interceptor time of flight and the magnitude of the necessary change in velocity required to home the interceptor to the target. Successful intercepts indicated the interceptor design provided the necessary velocity for the intercept trajectory and arrived at the threat before the threat burned out for a given launch location and threat trajectory.
The analysis demonstrated that the Reaper-based interceptor is capable of intercepting missiles in the boost phase given a feasible area of operations against both ICBMs and IRBMs. The analysis did show the Reaper-based interceptor was ineffective against the MRBM, whose short burn time and low burnout altitude precludes intercept during boost phase with this system.
This analysis shows that readily available technology could be combined to field a UAV-based system capable of a boost-phase kill against threats to both the American U.S. BPI capability.
https://www.wired.com/2011/02/unexpectedly-navys-superlaser-blasts-away-a-record/
The free-electron laser is one of the Navy's highest-priority weapons programs, and it's not hard to see why. "We're fast approaching the limits of our ability to hit maneuvering pieces of metal in the sky with other maneuvering pieces of metal," says Rear Adm. Nevin Carr, the Navy's chief of research. The next level: "fighting at the speed of light and hypersonics" – that is, the free-electron laser and the Navy's Mach-8 electromagnetic rail gun...
Currently, the free-electron laser project produces the most-powerful beam in the world. If it gets up to its ultimate goal, of generating a megawatt's worth of laser power, it'll be able to burn through 20 feet of steel per second. Just add electrons.
