The invasion of Iraq in my opinion was George W Bush trying to finish the war his father started years before. In the face of glaring evidence there were no WMD's. The world knew it, we all knew it. It made us look like a war hungry country who is willing to do what ever it wants, when ever it wants at any cost. And the cost was thousands of dead soldiers, and thousands more wounded both physically and mentally. Also a crushing debt to help pay for it.
The war was a complete disaster, and the world sees that. Also, America just looks overly aggressive when dealing with its problems. America invaded Iraq with the information that they had weapons of mass destruction, which they did not find. This made them look inept as well as quite dumb.
While the administration in the US saw a clear threat in Iraq, the connection made in the rest of the world was 9/11 led to invading Iraq - something that can be strongly argued, and is also somewhat random and definitely ill conceived. The rest of the world saw a random American invasion.
Yes, I think the 2003 invasion of Iraq had a negative effect on how the world views America. It showed the world that we have no problem upending the most ancient or stable cultures for the sake of enriching our defense contractors. It made things worse for us in the Middle East.
No, I do not think that the 2003 invasion of Iraq had a negative effect on how the world views America, because the world doesn't like America anyways. If they weren't criticizing us for that, they'd be criticizing us for something else. America cannot constantly worry about what the rest of the world thinks of us.