In "Casablanca," a movie I have seen at least a few dozen times, the cynical French police captain, Louis Renault (Claude Rains), shuts down Rick’s (Humphrey Bogart’s) saloon abruptly and arbitrarily.  “Gambling,” he harrumphs in fake outrage, shouting what everyone already knew about Rick’s: there was always gambling at Rick’s.  You drink at Rick’s, and you gamble at Rick’s, even though, on the books, gambling was forbidden in wartime Casablanca.

And so today in Washington, DC, we are harrumphed about the leaking of classified information: it has been widely practiced by both Democratic and Republican administrations for decades—that’s a fact.

It is the way administrations have traditionally gone around the normal rules of interviews and news conferences to get their story out to the American people.  And yet 30 Republican Senators, each as apparently shocked as Claude Rains by this discovery, have sent a letter to Attorney General Eric Holder demanding that he appoint a special prosecutor to find out whether President Obama’s White House has been leaking classified information to, in this case, the New York Times.  Of course, the White House has been “leaking” classified information to the Times.

Holder can save a lot of time and money by simply pulling a book off the best seller shelf—“Confront and Conceal” by Times reporter David E. Sanger—and read the following acknowledgment about his sources: “Almost every single member of the president’s national security team was generous enough to sit down and talk through their experiences, some more than once,” he writes.

Almost certainly the head of the president’s team, Tom Donilon, was one of them.  If Obama is commander-in-chief as president, Donilon is explainer-in-chief as national security adviser.

So it has been since McGeorge Bundy was President Kennedy’s national security adviser.  Henry Kissinger played this role for President Nixon, Zbigniew Brzezinski for President Carter, Condoleezza Rice for President George W. Bush and now Donilon for Obama.

I assume Rice was especially busy helping reporter Bob Woodward write four books about Bush’s war in Iraq, each one crammed full of “secrets” on almost every page.  The White House has even confirmed, for the record, that in some instances the president himself cooperated and then opened the door for others to do essentially the same thing.  The point is almost everyone has done it.

Leaking has now become a dirty word in Washington, easily exploitable for political purposes, because it suggests an underhanded, sometimes even illegal, way of conveying important information to the public.

The word “leaking” or “leaks” is muttered with a sneer of disapproval, even by officials who employ the technique on an almost daily basis. Why leak, it is asked, when an administration could just as easily hold a news conference or arrange a “background,” no-names interview?  Because most of the time it doesn’t want to appear to be the source boasting about, say, the bin Laden killing, or criticizing an administration official, or changing policy.  It would rather that the reporter, who loves secrets, serve as a witting or unwitting conduit to the public.  So the reporter gets a leak.

Many good reporters routinely pull bits and pieces of a story together and then, at the right time, ask an official for confirmation.  The official can confirm, deny or wink.  Is a wink a leak?  The official can also ask that the reporter not publish or broadcast a story to protect national security, and the reporter, after checking with his/her editor or producer, may end up agreeing with the government.  That happens, more frequently than imagined.

The bottom line is that national security leaks should not occur. They may, in fact, endanger lives and jeopardize highly-sensitive operations.  But they do happen; and if the history of recent decades be our guide, they are likely to continue.  Political vendettas are exposed.  Investigations are launched.  Officials are interrogated and many finger-printed.

Occasionally, after an extensive, expensive investigation, an official, for example, former Vice-President Dick Cheney’s friend and adviser, I. Lewis “Scooter” Libby, Jr., is indicted for leaking classified information to a reporter, because, as he later explained, he thought he was serving the vice president’s interest. In this case, the reporter ended up in a Virginia prison, because she refused to name her source.  Most of the time, though, reporters are hassled, some intimidated, but fortunately most just continue to do their job, occasionally publishing leaked classified information, and the Republic survives.

A suggestion for the Attorney General: rather than launch another investigation, which is likely to prove that administrations leak hot scoops to the media, which we already know, invite the 30 GOP Senators to a private screening of "Casablanca," let them see for themselves that there was gambling at Rick’s, and then serve them a drink.