A [State Department] spokesman said: "These revelations are harmful to the United States and our interests."
He added: "They are going to create tension in relationships between our diplomats and our friends around the world."
The government destroys evidence of prisoner abuse with impunity, refuse trial for people illegally abducted and tortured, assert your right to target and kill an American citizen, all without judicial oversight and what amounts to a "Just trust us," rationale. In the name of state secrets information and evidence of these crimes is being withheld. By its absolute non-cooperation, seemingly exercising absolute power, the government has in fact entirely ceded its power.
For criminalizing important information, like criminalizing anything else in tremendous demand (alcohol, marijuana, pornography), puts it in the hands of forces beyond their control, with their own interests. Wikileaks exists to fulfill that demand, and while it is odious in its exposure of individuals who could be killed for collaborating with the U.S., the government bears ultimate responsibility for creating these conditions in the first place (and subsequently dismissing Wikileaks' overtures to redact the names of those threatened).
It should also go without saying that exposing atrocities would not upset so many allies if there were not atrocities to expose.