The current US national defense strategy says the US must be capable of fighting one major war against a near peer enemy (nominally China) and defeating them:

https://thehill.com/opinion/national-security/558342-america...

The lack of basic weaponry seems to be a failure in that regard. Imagine if the US and Russia were fighting directly. The US may not have air superiority because of Russian jamming and air defense systems. Neither side wants to use nukes. So a long term ground and air war is a possibility, and the same seems possible with modern China. The Pentagon was not prepared for this as shown by what is happening in Ukraine. Instead they seem to have assumed that there will be no more big wars (not unreasonable until Russia decided otherwise and the US decided to "diversify supply chains" away from China) and they spent all the trillions on ever more advanced weaponry, never making large quantities of anything, but always starting the next new program. It is apparent they were caught by surprise, as was the EU who underinvested in defense for a long time. Now everybody is putting out contracts for new arms, but the manufacturers are going to take years to ramp up production. I expect this is partly caused by Congress in the US who tend to assume money solves everything, but in this case money can not buy time. Much of the material needed to make gunpowder and rocket motors comes from China, good luck ramping up production of those quickly if the US is fighting China. Part of the problem is outsourcing of manufacturing to other countries such that the US no longer has the ability to quickly switch industry to a war footing. US car makers rely on thousands of parts from other countries. That happened slowly over time, but even so the Pentagon wasn't keeping their eye on the ball and let capabilities slip away; car factories today could not make a tank, they are not set up for handling the heavy sheets of armor, all the robots would be useless, and there are no workers still trained in the old manufacturing methods. Yet another factor is secrecy, the US can't/won't give its most current weapons to Ukraine because that would reveal them to Russia and China. So all our super weapons can't even be used because of secrets. This shows a lack of foresight that not everyone fighting on our side in a war is going to have access to the most current US weapons. If it was NATO fighting Russia the EU do not and would not have the most advanced versions of the F35 and F22 for example, they'd have the export versions. There are factors unique to the Ukraine war, such as the time needed to train the Ukrainian military to use Western weapons (where the assumption was the US and EU already knew how to use them, so no problem for us) and the fear of escalation to nuclear war, but it seems the US military really was not ready for a long drawn out war in a remote location and they are obviously scrambling to adjust to that. A big concern recently is the realization that it would be very difficult for the US to fight against China (say to protect Taiwan) because it is so far away and we have few bases in the area. F22's and F35's can be refueled mid-air, but mid-air refueling planes can be shot down. Aircraft carriers are really vulnerable to anti-ship missiles. Basically it seems the world has changed (or perceptions of it anyway) and the US military has not adjusted (yet) to the that and didn't seem to see it coming. Maybe their hands were tied by Congress (for example demands to keep old planes flying instead of stocking more ammunition), we'll probably never know. The US has not fought a war against a near peer power in a long time, much of its planning for such a war has to be guesswork by people with little experience. If the US was attacked by Russia or China in a conventional war current munition stockpiles would probably be plenty, the long distance would work against the attackers. A war on the other side of the world is a very different set of logistical problems, yet may be considered just as crucial as defending home territory. If US military strategy says that is not worth considering, that's a decision to intentionally limit what kinds of wars can be fought. History would then judge whether that was a mistake or not.