No surprise that US military planners have been planning for the wars we've actually been fighting, which are low-intensity counterinsurgency operations. The goal is to minimize US and civilian casualties in an environment where we have superiority in air, land, and sea.
And it makes sense to do that. If we ever have a shooting war against Russia or China, the nukes will start flying and a) many people will die, but also b) our existing weapons supplies and industry will be destroyed.
We're building weapons that are well suited for the environment they are meant to be used in.
There's no reason to say that any war with Russia or China will have nukes.
Russia has been bluffing with this all the time, drawing "red lines" which will cause nuclear war - giving anything to Ukraine will have a nuclear response; giving artillery weapons to Ukraine will start nuclear war; giving HIMARS launcers to Ukraine; giving F-16 to Ukraine; giving ATACMS to Ukraine; saying Ukraine can shoot at all legal targets and not just those within its own borders will start a nuclear war... and yet there is no nuclear war.
In reality, a nuclear war cannot be won, but Russia is preparing for a big war or aggression against Western countries using conventional weapons, and is using nukes as a psychological weapon to extort and have its way and allow territorial expansion through wars of conquest using conventional weapons.
And it makes sense to do that. If we ever have a shooting war against Russia or China, the nukes will start flying and a) many people will die, but also b) our existing weapons supplies and industry will be destroyed.
We're building weapons that are well suited for the environment they are meant to be used in.