Well, both were right on their viewpoints, Let me put mine..
The Afgan/Iraq policy, war on Iraq etc would definitely have its drawbacks. But it gave a very strong message to the countries promoting terrorism that hurting united states is like playing with fire. Any country that is under suspect of supporting terrorist activities against America has a fear in their mind of their own existence. This fear factor helps in a great level in America's safety because terrorist movements would not get open support by the anti-American countries.
It is a fact that the country had spent billions of dollars and lost many invaluable lives. But last 8 years people in America could sleep peacefully without fearing terrorist activities, Passengers boarded to each flight with confidence. United states might have lost its respect in the last 8 years, True, American eagle lost some moral character, but it protected your freedom right? Just imagine of taking soft steps like peace talks after 9/11 attacks! Many pride buildings would have been disappeared by now!! Conducting peace talks with the people who don't understand the meaning of “Peace” is worthless. America is still on the war against terrorism.
In the the great epic of Mahabharata, Lord Krishna advised to the warrior (Arjuna) in the battlefield..
"If you know you are on the side of justice (Dharma), then it is your duty (karma) to fight against those who have joined the forces of injustice (Adharma) with selfless mind and not worrying about consequences".