Why should American citizens be concerned about North Korea advancements in ICBM technology? The obvious answer is that the technology enables North Korea to reach the US with ICBM missiles.
But there is an even deeper reason why Americans should be concerned and the answer is that the US has no reliable defense against ICBM technology today. The intent of Pres. Reagan’s Star Wars program was to protect America from attack by ICBMs but that program was never implemented to completion and many of the weapons systems that were developed initially were dropped by successive US administrations.
So the US strategy today is one of mutually assured destruction (MAD). In other words the US relies on the fear that we will annihilate an enemy with our nuclear weapons as sufficient to prevent that other nuclear power from ever attacking us. In other words we have virtually no ICBM defenses today except hit and miss technology which is still being developed. Reagan’s grand vision for a Star Wars program which was also called the Strategic Defense Initiative slowly dissipated into almost zero reliable technology to protect the US from a nuclear attack. When a nuclear missile is fired from anywhere in the world it can reach the US within 33 minutes. This “wait and pray” response is not good enough for nation of 330 million people literally waiting for their death to arrive in the form of a nuclear tipped ICBM missile. For this reason there is an urgent and over arching reason for a missile technology that will defeat an ICBM attack by our enemies including North Korea.