From an Aussie perspective...

Our foreign policy has been closely tied in with America's since 1942, when we made the decision to fight in the Pacific instead of in Europe. This lasted throughout WWII and since then we have still relied on the United States as our closest and strongest regional ally. In fact the ANZUS treaty guarantees we will support each other in the case of war.

We have supported America in most of its wars throughout the years, most noticably Vietnam until 1972, Afghanistan and Iraq (Though we will be pulling out soon). This is for a number of reasons:
1. National Interest - It was deemed to be in the "national interest" at the time to fight "communism" in the east. If the Domino Theory had indeed been true, then it was likely that we would have had many, many states to our north that would be unfriendly to us. So it was deemed to be in our ebst interests to support the UNited States, which we did almost to the end of the war.

2. Conservative Governments - Most of the 50s, 60s and 70s were dominated by conservative governments and in Australia this means that you are far more likely to be pro-American. I will return to this in a moment.

3. Political Necessity - Here in Australia if you are anti-US alliance and in politics you are instantly labelled as "weak on national security". The cynic in me will point out that wars are convenient from a political standpoint, as they assist in getting people re-elected - especially here.

So as I was saying in Australia the conservative governments are going to be more likely to hand a lot of our foreign policy over to the Americans, except for our rather unique role as peace keepers across the pacific islands. The further to the right wing a person gets, the more likely they are to support American foreign policy. I am on the fringe left and so are many people I know. We are all American-sceptic, however we are not anti-US because we realise that they are a necessity in terms of our very surivival against attack.

In politics there is bi-partisan support for continuing support for the United States, though there is disagreement on Iraq (Afghanistan remains bi-partisan... in fact I can only think of two parties who support us pulling out, of which 1 has some power). For this reason it rarely is sparked in national debate.

Pinpointing the general feeling for me will be hard, but I believe that we are anti-Iraq by a fair majority (at least 60-40. This poll may give you an idea. Its from 2 years ago, but it still gets the general idea. Also we recently elected a new anti-Iraq government), however we are broadly pro-United States. It is sort of hard to explain, but I would best summarise it as:

Our country supports stronger ties with the United States, but not all of its foreign policy objectives.

I'll try to answer any more questions as best I can.