I'm from the US so this isn't exactly an answer to your question, but I just wanted to add something. "Probably the most common argument is that we try to force our version of freedom and democracy on the rest of the world." This is something I hear about, especially about the Vietnam War. I can see how our involvement in Vietnam could present an image of the US thinking that we as a nation are responsible for making all other nations embrace our ideals. People could easily our actions as butting into issues that have nothing to do with us. Granted, a lot of the reason the US got involved was fear that communism would spread and taint us, but I can see how on the surface such a act seems pushy and even conceited.
However. . .when people are starving, being killed by their own leaders, or having their basic rights taken away, how can we not get involved? It seems that often the US is the only country with the power and the money to use on these things, and in the end it ends up looking like all we care about is making everyone agree with us. But could anyone expect us to just let things go? Can we let AIDS spread unchecked in Africa when we have the ability to do something about it? Would our national conscience permit something like that?
I love the US and I'm proud of the national desire to help suffering people all over the world. I can see, however, where people get the idea that the US is selfish and pushy. I think that because of our power and influence we are obligated to use it for the good of everyone. (Sorry, I didn't mean that to sound like Spiderman.)
A problem does come into play when we consider that our views of right and wrong may differ greatly from someone else's. Supporters of governments which we see as oppressive have every right to think of us as butting in. To them, we're not helping anything. But I still don't understand where people get off thinking we're evil for refusing to sign certain treaties. My Dad something once that I always try to keep in mind when considering political issues: the people making the decisions know far more about the situations and issues than the people at home do; try to remember that you might agree with them if you knew everything they do.
This wasn't supposed to be this long, but I hope it aids the discussion anyway.

ali"the long-winded"ssa