> There is also a movement to remove ICBMs from the Triad. If enemies launch toward the US, an ICBM counter attack launch only allows a 6 minute window.
The existence of ICBMs has been increasingly questioned in most of the countries that have them, with France leading the pack having phased them out of service. You've described one of the reasons, but the more important one is that their future ability to deliver warheads is now suspect. The SDI project was largely a comedy, but one of it's sub-projects, Brilliant Pebbles [1] was quite successful. While the work on the project as whole was ended, it's subcomponents lived on, most importantly the Exoatmospheric Kill Vehicle [2], the interceptor of the Ground-Based Interceptor [3], which was developed from the KE interceptor of Brilliant Pebbles. During the 00's, advancements in computers and especially digital cameras have made what were previously the hardest parts of Brilliant Pebbles have become not only realistic to implement but also quite cheap. At this point, it is widely believed that if anyone were to manufacture the ~5000 required interceptors and loft them into low earth orbit, this would provide nearly 100% effective missile shield against any exoatmospheric ballistic missiles.
The reason this was not previously considered debilitating to ICBMs was because of the limitations in available rocket launches, boosting all those interceptor satellites into orbit would have taken a very long time, during which you could either seek diplomatic solutions blocking their deployment, start deploying your own ASAT assets, or seek other solutions.
Enter SpaceX. Not only will ITS be the largest rocket ever developed, but they are intended to be very rapidly reusable, and SpaceX intends to build multiple of them operating from different pads. If they work as advertised, when they become operational the prompt space launch capability will go up by a factor of 100. This is necessary if we intend to make humanity a multi-planetary species. It will, however, also mean that the Chinese Premier can go to sleep one night in a world where ballistic missiles still work, and wake up into one where one power has deployed a functional ABM shield.
And if the other space launch operators intend to be able to compete with SpaceX in the market, they will have to build competing systems. This means that even the US is now looking into other ways to deliver warheads.
[1] https://en.wikipedia.org/wiki/Strategic_Defense_Initiative#B...
[2] https://en.wikipedia.org/wiki/Exoatmospheric_Kill_Vehicle
[3] https://en.wikipedia.org/wiki/Ground-Based_Interceptor