Clarifying the moral arguments
1. A nation that violates the individual rights of its own citizens cannot claim any "right" to enslave its people. Yemen's tyranny had no moral right to sovereignty.
http://aynrandlexicon.com/ayn-rand-ideas/collectivized-rights.html
2. "When we, of necessity, kill innocents in a retaliatory attack against an aggressor nation, we do not violate the rights of those innocents; their rights are violated by those who necessitate our retaliatory force."
https://www.theobjectivestandard.com/2006/10/reply-to-a-question-about-targeting-non-combatants-in-war/