After WW1, the big military powers thought they had learned their lessons - and they had. They went into WWII prepared to win WWI. After WWII, the bin military powers learned their lessons, and went into...various places, ready to win WWII all over again.
The big military powers are now discovering that they are once again prepared to re-fight the last war. Ukraine - out of sheer necessity - has developed new doctrines. Worldwide, the general staffs are left holding their multi-billion dollar assets that have suddenly become near worthless in this new kind of war. Using something like a Patriot to shoot down a suicide drone that cost 0.1% as much? Wars are ultimately decided by logistics, and that is how you lose a war.
There is a moral dilemma, though. Russia is...not a nice country. Their attack on Ukraine was not only unjust, it was also in direct violation of previous guarantees made to Ukraine. Meanwhile, Ukraine is deservedly known as the most corrupt country in Europe. Just as an example: where has all the money from the EU and other countries gone? Supposedly, all currently pending orders for new superyachts are for owners in the Ukraine. Maybe both countries can lose?