These countries are directly providing arms to attack Russia, thus they are directly involved. Iran and Houthis can do the same. You cant dictate who can join in a conflict. Imagine afghanistan calling foul for anyone other than US joining fight.
Russia agreed to that when it signed the Budapest Memorandum, it's written in black and white that we would provide assistance. I think the issue here is that you're complaining the response is disproportionate in case you suffer from Amnesia. The Houthis have launched 200 attacks against civilian targets in Israel. Israel blew up their oil terminal and it would be entitled to do a lot more. The Houthis have also attacked civilian shipping from dozens of different uninvolved nations, Israel hit their port. Furthermore, the whole war started because Hamas attacked Israel. The Houthis can indeed choose to join a war, but that means they forfit the right to not have the hell bombed out of them.
So if a militia in a ungoverned country attacks another that give right to invade? I thought sovereignty is sacrosanct.
It's sacrosanct until you attack someone, especially if that attack kills 1,000+ people. All nations have the right to take the necessary steps to defend themselves from such actions and the future occurrence of such, which in this case means wiping out Hamas and in the case of Afghanistan meant wiping out Al-Quaeda. Many nations would currently have the right to invade Yemen and wipe out the Houthis. The Houthis should consider that fact very carefully. What? Do you expect people to sit back and put up with militias from 'ungoverned' regions (that want to be recognised as states

) killing thousands of their citizens and do nothing?
According to which international law was the invasion of Iraq carried out again? Dont tell me they poked bush first.
The law of nine-stitches - they should have made the one stitch in 1991. Like it or not the UN sanctions were killing people indirectly and Saddam was killing people directly, that was driving recruitment for Al-Quaeda, which posed a threat to many countries. Saddam had also committed a million war crimes... use of chemical weapons on civilians, torture of civilians, hostages and PoWs, hostage takings, unprovoked invasion of Kuwait, deliberate environmental damage... etc. Should we allow someone to break all these international laws and get away with it? If so, what is the point in having the law? Enforcement of international law was the reason.
Still waiting for "1 million children" claim, buddy. Made-up statistics and Wikipedia pages couldn't even come close to that.
Okay 744,000. It's ballpark at least, unlike your bullshit.
The co-author of “Russia’s Abandoned Children: An Intimate Understanding,” says it dates back to the Soviet myth that all children got excellent care.
fortune.com
Again with this kindergarten-level argument, "they attacked first." That does not give you the right to bomb hospitals and destroy civilian infrastructure.
You should read international law on warfare more clearly. If an otherwise civilian structure is being used for a military purpose, it ceases to be a military structure. That said, Israel's maths on acceptable collateral levels are somewhat outside those of NATO.
Whilst we're on the subject of rights and law, you should check out the 1951 Refugee Convention. It states that all the civilians should have been evacuated via Egypt about 9 months ago. Imagine if Ukraine had left Bakhmut, Soledar and Avdiivka fully populated. All these civilians are forced to remain in Gaza because they're the only defence against Israeli bombs that Hamas has and many of the nations making humanitarian accusations know this full well, and are exploiting the fact prolifically. You want to complain, evacuate them to India. That should be the first response to any nations/citizens complaining. People would rather set up dubious charities and UN organisations in Gaza than evacuate a single person, tell me I'm wrong.
As if an arrest warrant makes any difference.
Well it didn't for India when Putin visited, that's for sure, Mr. Western Hypocrisy.
Just like the destruction of the Taliban?
The goal was to destroy Al-Quaeda, don't see Bin Laden about, don't see any 9/11-sized attacks. Killing the Taliban would mean killing everybody, it's possible obviously, but people would complain too much.