alt Hacker NewsI'm probably going to get flagged for this, but here goes anyway.
Russia absolutely has reason to not want Ukraine to join NATO. I'm not condoning the invasion, but I say it absolutely makes sense for Russia to carry it out. Not a reason to commit war crimes, or to cause any more suffering than necessary, but from a national security perspective it makes sense to want to disrupt the process of Ukraine joining NATO.
Only if you accept the hidden assumption that Russia is an antagonist toward the rest of Europe. Otherwise the common "national security" justifications make no sense, because Russia benefits immensely from other NATO members investing resources into the development of institutions in newer member states.
A former Russian foreign minister has labeled NATO "free-of-charge security" for Russia, because NATO membership requirements turn a country into a stable and predictable place. The best neighbors Russia has are in NATO, and much of that stability is directly attributable to their membership.