THROUGHOUT THE post-World War II history of the United States, a tension has existed between the demands of an open society and the need for intelligence to protect the country from danger. As a democracy we thrive on open debate, but also depend on spies who can work only in the deepest secrecy. At various times, the pendulum has swung from surprising openness and self-examination to intelligence operations that were locked up in the vaults for decades. The disclosure in The Post on Friday of new details of the intelligence budget is a good moment to reflect on these often-conflicting imperatives.

We need penetrating intelligence. Overseas adversaries can be difficult to locate and even harder to understand. They exist in shadowy terrorist groups and cyberwarfare units. Sixteen U.S. intelligence agencies, employing tens of thousands of people, form an impressive line of defense for the nation’s security. Their work must often be done in secret to protect sources, methods and ongoing operations, and we believe that a democratic society must understand and support the need for this secrecy.

At the same time, the intelligence community has clung for too long to an outdated Cold War mindset that any public information can be used by an adversary, so the best approach is to keep as much as possible under wraps. Some intelligence officials are probably horrified by the leak of the community’s budget request to Congress, provided to The Post by former National Security Agency contractor Edward Snowden. But this reaction is short-sighted. Publishing budget totals in broad-brush strokes will not damage the United States, and it may well stimulate a healthy discussion about priorities. Much of the budget information in this document should never have been classified, and it should not have taken Mr. Snowden to lift the veil.

The entire U.S. intelligence budget request, $52.6 billion for fiscal 2013, approximately equals the budget of the state of New Jersey, and is one-tenth that of the Pentagon. During the Cold War, about 40 percent of the CIA’s resources were devoted to the Soviet Union. Today’s threats are no less vexing: counter-terrorism, cyber operations and preventing proliferation are three of the top five objectives listed in the secret budget summary. U.S. adversaries quite likely already know this. So who were officials keeping it from?

After the Church committee hearings in the mid-1970s, after the 9/11 attacks and again after the recent disclosures of wide-ranging surveillance of telephone and Internet data, the intelligence community suffered a crisis of public confidence. Some of the criticism has been justified, and some not. But the larger point is that a democracy needs intelligence angencies, and it needs to accept that a fair amount of it must be done in secret. By the same token, the intelligence community should realize that a certain amount of transparency is essential to restoring and maintaining that public confidence. The country would be better off if its intelligence agencies and lawmakers took the initiative in promoting such measured openness.