Provide for the common Defense. Congress appropriates funds for national defense and has the power to declare war. By approving international agreements and the appointment of ambassadors, Congress also supports efforts to resolve conflict through diplomacy.
        
                    
             
        
        
        
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).
        
             
        
        
        
What is the role of Government?
establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, monitor the economy, businesses, and banks; maintaining the education system, roads, and public utilities, regulating the safety of food and medicine
        
             
        
        
        
The three religions that dominate the most densely populated areas in Asia are Islam, Christianity and  Buddhism.The most densely populated area in Asia is its South Asian region, which includes countries  like India, Pakistan, Bangladesh and Afghanistan. The people of these countries mostly observe these three religions, while India has predominantly Muslims and Hindus.
        
             
        
        
        
The answer is Physiological