1. I am not sure I agree with your assessment, even for "developed" countries. There are trends in Europe... European countries influence each other, but I am not sure that counts. You may be right, but if you had an objective measure I suspect the difference would be between Western Europe vs America.
I certainly would include Australia, New Zealand, Japan in the mix...as well as, as you noted, most of Western Europe.
We are not in the minds of most of those nations a "left leaning" nation. In fact, it seems to me that most would judge us VERY right leaning.
2. Of course if you measure a different crowd you will find a different "middle" position.
Of course. So?
3. I am curious about your use of the term "developed" countries. This would likely exclude most people from Muslim nations and traditional African cultures. Would this exclude Russia, China, Iran?
This seems like an arbitrary distinction to make.
I doubt Russia, China, or Iran would consider us to be a left-leaning nation...just as I doubt any of the countries mentioned above would.
As for the Muslim nations and African cultures...is you think they would...I'd be interested to hear your case for why you do.
I suspect most of the world sees us as a predominantly conservative nation.
I may be wrong.
But I disagree with your opening suppositions.