Alfred Thayer Mahan was a United States naval officer, historian, and one of the most influential American authors of the nineteenth century.
He argued that modern navies needed repair and coaling stations, which would not be dependable if controlled by other nations. This reasoning implied a justification for American acquisition of colonies to develop port facilities throughout the world.
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).
They gave soldiers better advantage at defeating the enemy and defending the country.
Examples Include:
Tanks
Guns
Technological advances such as Airplanes
Rights that they thought they had but not really