Here we have a fundamental disagreement about what it means to be Presidential. For me, it's about leading by example, getting the job done, and part of that job is diplomacy. You can't get other countries to go along with your ideas, or get them to pony up their good ideas for you to share, if they think you're a dick because you're acting like a dick. Leadership requires mutual respect and cooperation. Conversely, some people view being President as all about force. Never giving an inch, making people do what you want whether it is good for them or not. That way causes more problems than it solves.
*wist* Imagine how much progress in world diplomacy could have been made if President Obama had been free to do things like this all along.