The word "we" is such a small word in our language. But, depending how it is used, it has at least two very distinct and powerful connotations. When used by anyone in behalf of a peer group, a group of like-minded people, it expresses a form of "solidarity" among all those in that group.
The word "we" is also used by a "leader" in order to "soften" the harshness of his or her "authority" by slyly asking his subordinates to "agree" to do something; even though, any real disagreement wouldn't actually be tolerated. This is opposed to that same leader giving a direct command. Certainly, "we can do this" is much more acceptable to an employee than "I want you to do" this, or that, or the other thing. This is really a form of reverse psychology and one that is used constantly in business by supervisors/managers and in the social world by teachers, counselors, doctors, psychologists, etc. But, make no mistake, the use of the word "we" in this context strictly implies a form of boss/leader and subordinate relationship.
Barack Obama uses "we" constantly in all of his speeches. Clearly, he uses it in the form of "a leader" asking for people to follow in some endeavor. I suspect it is a technique that Senator Obama learned, quite well, in his role as a community organizer; working in Chicago. This plays well to the domestic crowds that come to see him at his various campaign venues. They clearly see him as their leader and they enthusiastically want to follow him in "all" his "we" and "we can" directives. They certify this committment by loudly erupting in cheers for him.
Yesterday, Barack Obama gave his speech in Berlin, Germany. As usual, he used his "we" and "we can" word technique throughout that speech (Click to see the full text from the Drudge Report). But, unlike here, the crowds weren't in riotous agreement. They were generally subdued; except, of course, when he talked about getting out of Iraq. I think Obama made a mistake by using the "we" technique in that speech. His leadership was being implied in its use and the Germans aren't hardly his subordinates. In fact, most of Europe reacts negatively to America's leadership in anything. And, they don't need another American telling them what to do. In a way, I believe the bloom may have come off the rose in that speech; as far as the Europeans are concerned. But, only time will tell as they finally figure out how presumptive that speech really was.