Conservatives don’t seem to be “attacking” Obama so much as expressing a lack of surprise at his hollow recitation of trigger phrases. Consider the ending to a piece by Andrew Ferguson:

To pump a little vigor into his limp sentiments, Obama attached them to a hypnotic refrain. “This is the moment,” he said in Berlin, repeatedly. But where’s the urgency come from? What’s the rush? In the long train of platitudes he suggested no discrete, definable policy that needed to be adopted urgently, beyond his call to unity, which isn’t a policy but an aspiration. You get the idea that the urgency doesn’t arise from an assessment of reality but from a rhetorical need. He’s got to keep the folks on their toes somehow.
Obama couldn’t come to Berlin and deliver a speech full of portent, as Reagan and Kennedy did before him, and as his publicists suggested he might. For all the talk about this being our time and us being the people, Obama shows no sign of really believing we live in portentous times. This is surely part of his appeal. It’s not surprising that when he came to Berlin and said nothing at all, none of his admirers seemed disappointed. After eight years of overheated history, nothing comes as a relief.

For his part, Jeff Jacoby offers a notable contrast:

… Obama seemed to go out of his way not to say plainly that what saved Berlin in that dark time was America’s military might. Save for a solitary reference to “the first American plane,” he never described one of the greatest American operations of the postwar period as an American operation at all. He spoke only of “the airlift,” “the planes,” “those pilots.” Perhaps their American identity wasn’t something he cared to stress amid all his “people of the world” salutations and talk of “global citizenship.”
“People of the world,” Obama declaimed, “look at Berlin, where a wall came down, a continent came together, and history proved that there is no challenge too great for a world that stands as one.” But the world didn’t stand as one during the Cold War; it was riven by an Iron Curtain. For more than four decades, America and the West confronted an implacable enemy on the other side of that divide. What finally defeated that enemy and ended the Cold War was not harmony and goodwill, but American strength and resolve.

Back to Ferguson:

The thing about wars, even cold ones, is that the world doesn’t stand as one; that’s why there’s a war. And in the Cold War the Soviet side was as united as the West; more so, probably. Left out of Obama’s history was any mention of the ferocious demonstrations against the United States in the streets of Paris and West Berlin during the 1960s and 1980s, when American presidents were routinely depicted as priapic cowboys and psychopaths. Probably a fair number of the older members of Obama’s audience had been hoisting those banners themselves 25 years ago.

Obama’s fellow travelers have been on the wrong side when American confidence and fortitude have been required. Their intellectual forerunners decried actions that today they must embrace, however indirectly. Not through the toil of leftists did the Berlin Wall fall. And the empty echo to be heard in his representation of history and its lessons for the present and future suggest that a President Obama would not make those sorts of courageous decisions by which great men carve a path through history toward freedom.