For me, the European trip was all sorts of style and very little substance. The president spent the entire campaign complaining that President Bush had alienated the world and as such, we can't get any cooperation. So, he asked for NATO troops in Afghanistan and got a few trainers. North Korea shot off a missile and he went to the UN. Only at the UN, he got absolutely nothing. Furthermore, he suggested in Turkey that Turkey became a part of the EU. This created an immediate rebuke from most of the official EU nations. So, on foreign policy, all the popularity translated into nothing of substance.
Economically, the president got similar results. The rest of the world dismissed out of hand his idea for a world stimulus. Most of the rest of the world simply can't afford that kind of debt. The only agreement to come out of the G20 is an agreement for a world regulatory body. This is an idea championed by Nicholas Sarkozy and he threatened to leave the meeting without it.
It's very easy to tell just how much of a failure the trip was. Just look at how supporters viewed the trip.
It is difficult to see this trip as a failure. He was warmly received--which is not insignificant given the diminished stature of the United States overseas that made it extraordinarily difficult to obtain assistance on international affairs—promises were made to deal with the financial crisis, and Obama was able to open some dialogue in parts of the world where dialogue has been shut down for years. The critics might have something to talk about down the line, but as an opening move this certainly cannot be characterized as a failure.
With nothing of substance to point to, you immediately look at tangential matters. Of course, he was able to open a dialogue. That's what happens when world leaders get together for a week at a time. What kind of a low bar is this? Are we now treating as success the mere fact that our president was able to speak at length with other world leaders? Isn't that what is supposed to happen?
Of course he was warmly received but then denied everything he asked for. Either his supporters are blind or they are hoping the rest of us are. If a warm reception and open dialogue are the standards for success, they have set the bar awfully low for the president.