The dangerous elements of the Wilson Plame Affair, or Libbygate, where one American citizen has been found guilty of felonies, are war, intelligence gathering, espionage, presidency, American public, credibility, press, partisanship, and falsehood.

Once before in American history, the American people were asked to make a profound decision about war based upon disputable and unverifiable intelligence evidence without any more certainty than was true in 2003 with regard to the Iraq war.

And it is fair to measure the Bush administration today not on the basis of the clumsy, inarticulate, and peculiar falsehoods of one man, but rather on how it handled the intelligence it had at the time and how it regarded its mission to persuade the American public to go to war.

It was the Zimmerman Telegram affair, in the winter of 1917, and it turned America from a prospering neutral into a belligerent in World War I. What is striking is that the same values were at risk during the Zimmerman Telegram affair as are found in the Wilson Plame Affair: the fate of the world, the worth of intelligence, the nastiness of espionage, the truthfulness of the president to the American people, and the manipulation of the press and enemies to win a debate.

The long-term result of the Zimmerman affair was invasion, massacre, chaos, revolution, and collapse and America entangled in a series of long, draining wars over 70 years on a distant continent. But at the time, an immediate result was much argument about intelligence in Washington, Mexico, London, and Berlin. And by no means was the debate settled to anyone’s satisfaction, especially not to the American people’s comfort.

The established facts now, after all the parties are gone, are that the German foreign office conceived of a plan to entice Mexico to declare war on America in order for Mexico to recapture its lost territory of the Western states, which would keep America too preoccupied to enter the war against Germany. The Mexicans were also told that the Japanese would fight alongside them.

This whole plot was outlined in a single telegram, written by the German foreign secretary, Arthur Zimmerman, and sent by American diplomatic cable — provided free of charge by the peace-loving President Wilson — to Mexico City via Copenhagen, London, and New York.

The sneaky British secretly intercepted it in London, but this left the British in a quandary. How could they convince the “Too proud to fight” Wilson that it was a true telegram? And how could they do this without offending America by admitting Britain was spying on American peacemaking efforts?

The British gambit to convince Wilson was farfetched, involving stealing another version of the telegram in Mexico City, decoding it, and then delivering it to the American ambassador in London, claiming it was the product of a confidential friend, Senor H, which was a bald lie.

Wilson was handed the product on February 25. He blinked, since it upset his worldview, and passed it to the open press on March 1.

Still, no one much wanted to believe it. Mexico was going to invade America to retake California? And the Japanese were going to attack the Philippines and Hawaii?

After a month of debate in Congress, influenced heavily by the German decision to launch unrestricted submarine warfare against American shipping that was profitable for Wall Street, Congress acceded to Wilson’s request for a declaration of war.

Recently, the original of the decoded telegram handed by the British to the American ambassador in London, who sent it on to Wilson, was discovered in a trunk. Most of the rest of the paper trail was destroyed. Ask yourself now, how did Wilson, Congress, the American press, and the American people know at the time that the Zimmerman Telegram wasn’t entirely a British fabrication?

The true answer is that, at the time it most mattered, no one had any confidence in the Zimmerman Telegram. It was a true work of intelligence gathering, but no one could prove it. And it was also an espionage trick of the desperate British, but no one could prove it.

And it made it easier for Wilson to convince the public to support a war declaration when it was released to the press, but the press had no verification when they published it. And it made it easier for Congress to declare war on April 6, 1917, but not one member who voted affirmative could be certain that the telegram was a valid document.

The Bush administration’s intelligence on the war in 2003 was vastly better than Wilson’s was on Germany in 1917. And if Wilson had sent an ex-ambassador to Mexico City to ask a preposterous question, “Are the Japanese going to join you in an attack on America?” and the agent had returned to Wilson, via State, “There is no evidence, sir,” and then written it up for the New York Times, we can suppose a proto-Libby might have invented himself while the Wilson administration campaigned in the newspapers for war.

When someday 90 years from now documents are found in a trunk that demonstrate there was a fantastic conspiracy to procure nuclear weapons for Iraq as well as its kindred of Cain, Libby will still be guilty of lying under oath to a federal grand jury.

Mr. Batchelor is host of “The John Batchelor Show,” now on hiatus.