Any western government or leader surprised that Ukraine is now talking about developing their own nuclear weapons program needs to understand that they wouldn’t even be considering that if we had just fucking held up our end of the deal.
With the Budapest Memorandum, they surrendered their (former Soviet) nukes in exchange for security guarantees. The guarantees ended up being worth less than the paper they were written on. Ergo, Ukraine, seeking security guarantees on its own terms, feels compelled to re-develop nuclear weapons technology, because that’s a guarantee nobody’s going to be able to forcibly take from you once you have it.