How real is the Obama effect?

Andrew Sullivan flags the latest data point on the rebound in America’s image abroad: 

Views of the US around the world have improved sharply over the past year, a BBC World Service poll suggests.

For the first time since the annual poll began in 2005, America’s influence in the world is now seen as more positive than negative.

The improved scores for the US coincided with Barack Obama becoming president, a BBC correspondent notes.

As in 2009, Germany is viewed most favourably while Iran and Pakistan are seen as the most negative influences.

Nearly 30,000 people in 28 countries were interviewed for the poll, between November 2009 and February 2010.

Now, on the one hand, this is particularly impressive, because the people of the world are in a really sour mood.  If you look at the entire report, the United States is the only great power and one of only two countries (South Africa is the other) to record an uptick in positive influence over the past year.  This is also fully consistent with other surveys demonstrating an “Obama effect.” 

On the other hand, it’s worth asking whether this boost in U.S. favorability ratings has yielded anything in the way of tangible policy gains.  Sullivan avers that: 

[I]n trying to defuse as well as defeat Jihadist terror, this kind of profound change could serve America’s interests well. The idea that a better reputation abroad is meaningless uplift is foolish. It helps the US leverage its power to greater ends. The more popular the US is, the likelier it is to have a positive impact on other countries’ leaders.

There’s some truth to this — otherwise you don’t get the largest number of world leaders on American soil since the founding of the United Nations.  That said, I do wonder just how much leverage this kind of soft power carries with it.  Consider the ability of the U.S. to enact multilateral economic sanctions.  The Bush administration, at the depths of its unpopularity, was still able to get the UN Security Council to pass three rounds of sanctions against Iran, as well as measures against North Korea.  The Obama administration, despite a serious effort to open a dialogue with Iran, is encountering resistance from China, Brazil, and Turkey in its efforts to craft another round of sanctions. 

All else equal, it’s better to see these numbers going up.  I’m just unsure of how much this translates into usable leverage.

What do you think?