Here’s Putin:
We are often told our actions are illegitimate, but when I ask, “Do you think everything you do is legitimate?” they say “yes”. Then, I have to recall the actions of the United States in Afghanistan, Iraq and Libya, where they either acted without any UN sanctions or completely distorted the content of such resolutions, as was the case with Libya. There, as you may know, the resolution only spoke of closing the airspace for government aircraft, while it all ended with bomb attacks and special forces land operations.
Our partners, especially in the United Sates, always clearly formulate their own geopolitical and state interests and follow them with persistence.
The U.S. military intervention in Afghanistan could be defended as self-defense on the theory that the Taliban government harbored Al Qaeda, and it was later ratified by the Security Council. But Putin is right that the 2003 Iraq intervention was clearly illegal, and that the military intervention in Libya went beyond the terms of the Security Council authorization.
Tu quoque (“you too”) defenses are not recognized in international law; but they can be effective as appeals to fairness and ground arguments that the law is unjust and should be abandoned. But Putin does not go on to argue that because the United States violated the use of force rules, Russia can as well. Instead, he says:
Our approach is different. We proceed from the conviction that we always act legitimately. I have personally always been an advocate of acting in compliance with international law. I would like to stress yet again that if we do make the decision, if I do decide to use the Armed Forces, this will be a legitimate decision in full compliance with both general norms of international law, since we have the appeal of the legitimate President, and with our commitments, which in this case coincide with our interests to protect the people with whom we have close historical, cultural and economic ties. Protecting these people is in our national interests. This is a humanitarian mission.
And so it turns out that even if the United States is an international lawbreaker, Russia chooses to take the high road and comply with international law, or so Putin claims. The reason for this approach is surely that Putin sees an advantage in the current system that grants Russia a veto in the Security Council even if this means that Russia must gin up a feeble legal rationale for its unilateral intervention in Ukraine.