In a speech on Jan. 17, President Obama spoke of the challenge of a world “that is remaking itself at a dizzying speed.” The subject of his address at the Justice Department was the complex issues of security, privacy and the limits of government power raised by revelations about the National Security Agency’s spying. That debate continued to rage through the last week. But Mr. Obama could have been speaking as well about conflicts in places like Syria and Ukraine, which seemed to become more intractable with every effort at resolution.

Secrets and Contractors

When the first of Edward Snowden’s cache of secret documents leaked out nearly eight months ago, the initial presumption was that the United States had another WikiLeaks on its hands — a painful and embarrassing breach of confidentiality that would require fixing and explaining, but not necessarily changing, what the government was trying to do. Before long, however, the revelations about the extraordinary spread of the N.S.A.’s global surveillance raised a host of questions about the balance of liberty and security at a time, as Mr. Obama put it, when “there are fewer and fewer technical constraints on what we can do.”

Much of the debate has swirled around legality, constitutionality and morality. But the questions underscored last week were more practical: Has the N.S.A.’s vast sweep of phone records, and specifically those of its own citizens, made us safer? Can we trust the government and its network of private contractors with so much data?

One development was the revelation that Mr. Snowden’s background had been vetted by a private firm contracted by the government to perform sensitive security checks, and that the company, U.S. Investigations Services, had submitted more than 650,000 incomplete investigations. It was not immediately known whether Mr. Snowden’s background check was among the flawed ones, but it is noteworthy that Mr. Snowden was working for another private contractor, Booz Allen Hamilton, at the time he took off for Hong Kong with his trove of secrets. The complaint filed by the United States government against USIS thus underscored how extensively the government relied on contractors not only to do its secret work, but also to vet those very contractors.