He successfully repelled an invasion by rival claimant Herald Hardrada of norway
Yes. Just so you know, I'm only in 11th grade, so I might not be using the right vocab, but I'll try my best.
It can be justified the same way that it was during the Korean War. In order to repel communism in South Korea, the US troops were launched. This was a unilateral military action. In the same way that the US used the Monroe Doctrine to help aid and enforce their rule in other places, this is what happened during the Iraqi War. The US saw an unjust system of government reigning unfairly, so they intervened to overthrow it. The justification there was that they should have been able to choose their own government (in short, they should have a fair and free democracy).
