As a Brit, I can share their frustration..
It was never full support of the American people. Ever. Find a genuine unbiased poll that says 100% support for the war, and I will give you $100.
It's a common mistake to paint an entire nation based on the actions of it's government.
The UK also invaided Iraq. I objected from the very beginning, I voted for a different political party at every available opportunity, and gave my objections in writing to the 2 MP's I've had since the war began.
So am I ashamed of my government. Yes.
Do I look bad? No.
Doug