When—and it is most probably now a question of when, rather than if—Israel is forced to bomb Iran's uranium enrichment facilities, the Israeli government will immediately face a cacophony of denunciation from the press in America and abroad; the international left; the United Nations General Assembly; 20 secretly delighted but fantastically hypocritical Arab states; some Democratic legislators in Washington, D.C.; and a large assortment of European politicians. Critics will doubtless harp on about international law and claim that no right exists for pre-emptive military action. So it would be wise for friends of Israel to mug up on their ancient and modern history to refute this claim.
The right, indeed the duty, of nations to proactively defend themselves from foes who seek their destruction with new and terrifying weaponry far pre-dates President George W. Bush and Iraq. It goes back earlier than Israel's successful pre-emptive attacks on Iraq's Osirak nuclear reactor in 1981 (not to mention other pre-emptive Israeli attacks like the one on the Syrian nuclear program in 2007). It even predates Israel's 1967 pre-emption of massed Arab armies, a move that saved the Jewish state. History is replete with examples when pre-emption was successful, as well as occasions when, because pre-emption wasn't employed, catastrophe struck.
When it became clear that the Emperor Napoleon was about to commandeer the large and formidable Danish navy stationed at Copenhagen in 1807, the British Royal Navy attacked without a declaration of war and either sank, disabled or captured almost the entire fleet. No one screamed about "international law" in those days, of course, any more than statesmen would have cared if they had. Neither did Winston Churchill give any warning to the Ottoman Empire, a German ally, when he ordered the bombardment of the Dardanelles Outer Forts in November 1914, also without a war declaration.
Similarly—though there were plenty of warnings given—Britain was formally at peace with her former ally France in July 1940 when Churchill ordered the sinking of the French fleet harbored near Oran in French Algeria, for which he was rightly cheered to the echo in the House of Commons. The sheer danger of a large naval force falling into Hitler's hands when Britain was fighting for its survival during the Battle of Britain justified the action, and the exigencies of international law could rightly go hang.
Looking further back, and thinking counterfactually, as historians are occasionally permitted to do, there have been several wars in which devastating new weaponry spelled disaster for the victims of the power developing them, and the victims would have been much better off using pre-emption.
In the Middle Eastern context, Goliath ought to have charged down David long before he was able to employ his slingshot and river pebbles to such devastating effect. The Egyptians should have attacked the Hittites as soon as the Egyptians suspected they were developing the chariot as a weapon of war. Had the Mayans and Incas assaulted the conquistadores as soon as they stepped ashore—and thus before the Spaniards could deploy their muskets, horses, metal armor, hand-held firearms and smallpox to crush them—they might not have seen their civilizations wiped out.
The Mamelukes and Janisseries shouldn't have waited to be slaughtered by Napoleon's cannon at the battle of the Pyramids; the Khalifa needed to hit Kitchener on his way to Omdurman in the River War of the late 19th century, not once he'd set up his machine guns on the banks of the Nile; and so on.
Often in history, massive pre-emption has been the only sensible strategy when facing a new weapon in the hands of one's sworn enemy, regardless of international law—the sole effect of which has been to hamper the West, since those countries that break it can only be indicted if they lose, whereas civilized powers generally have to abide by its restrictions.
Consider a counterfactual analogy that will weigh heavily on Israeli Prime Minister Benjamin Netanyahu as he struggles with his historic decision. If the French Defense Minister André Maginot, instead of investing so heavily in his defensive line in the mid-1930s, had thought offensively about how to smash the German army the moment it crossed the Versailles Treaty's "red lines" in the Saar and the Rhineland, some six million Jews might have survived.
The slingshot, chariot, musket, cannon, machine-guns: All were used to devastating effect against opponents that seemed to be stronger with conventional weaponry but were overcome by the weaker power with new weapons that weren't pre-emptively destroyed. Since President Obama's second inaugural address has made it painfully obvious that the U.S. will not act to prevent Iran from enriching more than 250 kilos of 20% enriched uranium, enough for a nuclear bomb, Israel will have to.
Mr. Netanyahu might not have international bien pensant opinion on his side as he makes his choice, but he has something far more powerful: the witness of history.
Mr. Roberts, a historian, is the author, most recently, of "The Storm of War: A New History of the Second World War" (Harper, 2011).
A version of this article appeared May 1, 2013, on page A17 in the U.S. edition of The Wall Street Journal, with the headline: The Case for Pre-Emptive War, From Goliath to the Dardanelles.