Presidents and political leaders seem obliged to talk down to the people about the delicate, disagreeable and dangerous game of international espionage. Keep it simple is the rule; there are good guys, bad guys and a whole lot you shouldn't trouble yourself thinking about.

Old pros in intelligence -- and I am talking about real spies, not the high- technology stuff -- talk differently. They talk cynically, up front. Knowing it's a jungle out there, they do not confuse espionage with crime in the streets. The talk we have been hearing about spying recently -- and the case involving Israel in particular -- is a perfect illustration of why, if you want a rounded view, it's good to stick with the pros.

In his recent Saturday radio address on the subject, for example, President Reagan dwelt on the threat to the West from a growing swarm of KGB agents working for the Soviets and their satellites in the United States and around the world.

"There is no reason to sugarcoat reality," the president said, adding: "The free world is today confronted with some of the most sophisticated, best orchestrated efforts of theft and espionage in modern history."

True enough. But when the president promises to "root out and prosecute the spies of any nation," and insists "we will let the chips fall where they may" -- and still can't bear to mention the Israeli case -- he is not just sugarcoating reality. He is doing a disservice to public understanding.

The same may be said for the arguments we are getting from Israel's best American friends: that the Jonathan Jay Pollard case is the work of irresponsible, overzealous underlings. "We can straighten this out in no time," Sen. Pat Moynihan (D-N.Y.) said the other day.

If so, why did it take Israel a full week to clear its throat before issuing an apology "to the extent that (the Pollard case) did take place"? Why did even that non-apology have to be negotiated by the U.S. secretary of state?

You might have thought that if someone offered to sell U.S. military secrets to Israel, the Israelis would have warned their good American friends about a serious threat to U.S. security instead of apparently exploiting it for their own purposes. But that would not be in the nature of the U.S.-Israeli relationship, nor in the nature of the espionage games even friendly nations play.

The United States and Israel cooperate on intelligence matters only up to a point. The United States holds back things that would threaten relations with its Arab friends in the region. The beleaguered Israelis venture off from time to time without the slightest sense of obligation to counsel with the United States in advance.

The old hands take it for granted that Israel conducts intelligence operations in the United States. They assume as well that after assorted surprises -- the 1956 Suez war, the Israeli bombing of Tunisia and Iraq, and the full scale of Israel's war in Lebanon -- the United States has been doing its own intelligence checking on Israel.

And yet when they say so out loud -- well, consider the reaction the other day when former director of central intelligence Richard Helms did just that. He said that "the only sin in espionage is getting caught." That "friends spy on the United States surprises me not at all." When asked on ABC's Sunday talk show whether the United States could conceivably be spying on its NATO allies, he replied: "I hope so."

Well you could have knocked Sam Donaldson over with a classified document. If the only crime was being caught, why have espionage laws, he wanted to know. By that standard, Donaldson pressed on, we might as well cheat on our income taxes -- as long as we don't get caught.

Helms struggled in vain to explain the difference between taxes and espionage. He tried to explain that the subtleties and just plain lawbreaking involved in intelligence and counterintelligence activities are not so much a matter of cops-and-robbers as of damage limitation. But the espionage struggle in the shadows between friends as well as adversaries around the world is not a subject that lends itself to Sunday talk shows or to presidential radio chats with the folks.

Still less does it lend itself to promises to "root out" the rascals, whoever they are, letting "chips fall where they may." Don't tell anybody, but we have some chips of our own at risk in this game.