Dictators are not in the habit of admitting mistakes. But if Adolf Hitler and Benito Mussolini could talk from the flames of hell, they might have advice for today’s America: don’t give up your aircraft carriers.

Carriers today are being blown out of the water by critics who say they have become nothing more than expensive targets in an age of hypersonic ship-killer missiles. Should war erupt, say critics, U.S. carriers in the South China Sea would be overwhelmed by waves of missiles, aircraft and submarines.

Whether or not carriers are actually this vulnerable is another matter. The question here is more basic: What happens when navies operate without carriers? For an answer, we can turn to World War II, and more specifically the navies of Nazi Germany and Fascist Italy (we’ll leave out the Soviet Union, whose navy played a minor role in the war).

Germany and Italy did in fact dabble with aircraft carriers. Germany laid down the Graf Zeppelin in 1936, which still hadn’t been completed by 1945. The Italian passenger Roma began its makeover into the carrier Aquila in 1941, and still wasn’t finished when Italy surrendered in 1943.

Thus the mighty battleships and cruisers of the German and Italian surface fleets either had to operate within range of land-based aircraft, or do without air cover at all. How did this work out? Let’s go back to 1941 to consider two famous examples.

In May 1941, the legendary German battleship Bismarck sortied from the French port of Brest on a mission to raid British shipping lanes in the North Atlantic. Its companion was the heavy cruiser Prinz Eugen, a powerful warship in its own right—but not an aircraft carrier.

For a few days, the Bismarck terrorized the North Atlantic, culminating on the May 24 Battle of the Denmark Straits, where it humiliated the Royal Navy by destroying the battlecruiser Hood and damaging the battleship Prince of Wales with a few well-placed shots. Slightly damaged by a hit from the Prince of Wales that caused a fuel leak, the Bismarck headed toward sanctuary in the French port of Brest while the Prinz Eugen continued its mission.

With Britain’s centuries-old maritime prestige on the line, the Royal Navy flung everything it had in a desperate race to catch the Bismarck before it reached France, including the aircraft carrier Ark Royal and its obsolete Swordfish biplane torpedo bombers.

The odds were not in Britain’s favor. The weather was bad and the German battleship didn’t even have to reach Brest. The Bismark only had to get within range of Luftwaffe aircraft—perhaps a hundred miles or so beyond the French coast—before the threat of German bombers would force the British fleet to give up the pursuit.

Like the chase scene in a cliffhanger, the Bismarck came so very close to safety. The British ships were low on fuel. Luftwaffe crews at their French airfields waited eagerly for the battleship to get within range. Instead, just twelve hours from succor, the Bismarck was spotted by British flying boats on May 27. The Ark Royal launched fifteen Swordfish into appalling flying weather, with the German battleship forty miles away, still out of range of the British fleet’s guns. Despite the bad weather and the fading light, one Swordfish managed a lucky torpedo hit that jammed the Bismarck’s rudder so badly that the ship could only turn in circles. When the British fleet caught up the next morning, the outcome was inevitably a watery grave for Hitler’s battlewagon.

And that grave was just three hundred miles from the French coast.

In the spring of 1941, Nazi Germany possessed the most powerful land-based air force in the world. But all the führer’s aircraft and all the führer’s pilots couldn’t save the Bismarck, because they couldn’t reach it.

The outcome might have very different if the Bismarck had been accompanied by an aircraft carrier like the Graf Zeppelin. Even just a handful of German carrier-based Me-109 fighters could have torn up the slow Swordfish, or at least spoiled their aim enough for the torpedoes to miss and the Bismarck to escape.

Now we turn to Italy. At first glance, Italy didn’t need aircraft carriers because it was an aircraft carrier. The Italian Peninsula and Sicily, jutting into the Central Mediterranean, were covered with airfields. In the narrow waters of the Middle Sea, the Italian Navy could operate within a couple of hundred miles of land-based bombers, fighters and reconnaissance aircraft in Italy, Greece, Crete and North Africa.

Why should the Italy Navy spend money on aircraft carriers when the Air Force could handle the air war? The answer became clear at the Battle of Cape Matapan in March 1941. Seeking to intercept British troop convoys headed to Greece, the Italians dispatched a battleship and six heavy cruisers from Italy to a point off the Greek coast. They were supposed to have been protected by land-based fighters.

On March 28, 1941, the Italians ran into a British force of three battleships and the aircraft carrier Victorious. After an inconclusive battle between Italian and British cruisers, the Italian fleet withdrew and headed back to base. The British realized that their battleships couldn’t catch up to the Italian force before nightfall—but the Swordfish torpedo bombers on the Victorious could. One Swordfish put a torpedo into the Italian battleship Vittoria Veneto’s propellers, knocking it out of the fight, while another torpedo left the heavy cruiser Pola immobile in the water. When two other heavy cruisers came to the aid of the Pola, they were attacked in a night battle by the British battleships, which sank all three cruisers.

And what of the Italian land-based fighters, which should have swatted the slow Swordfish biplanes from the sky? They never showed. The Italians discovered what the Japanese and Americans learned in the Pacific: land-based air support for fleets often failed, due to problems with coordination, communications, air force pilots untrained to fly long distances over water and the strain of maintaining continuous air patrols far from land.

It’s not that aircraft carriers would have been a panacea for the Axis. Hitler didn’t need the vast fleet of carriers the United States sent to the Pacific in 1945. Every carrier built would have meant fewer tanks and aircraft to stop the Soviet avalanche that eventually trampled Germany in 1945. As for Italy, it didn’t have the resources to build many carriers.

But Germany and Italy didn’t need many carriers. In early 1941, when the war in Europe hung on a knife edge, a couple of carriers at the right time and place could have made a profound difference.

None of this means that today’s U.S. Navy necessarily needs ten carriers (President Trump has spoken of increasing this number to twelve), or that the carriers that America does need should be $13 billion Ford-class behemoths. It’s also true that modern aircraft have much longer ranges in 1941, while computers and advanced communications systems enable land-based aircraft and ships to cooperate in ways unimaginable seventy five years ago.

But the utility of the aircraft carrier concept remains. As two of history’s most infamous tyrants can attest, having your own floating airfield to provide air cover when and where your fleet needs it can be a matter of life and death.

Michael Peck is a contributing writer for the National Interest. He can be found on Twitter and Facebook.

Image: U.S. Navy MH-60 Seahawk helicopters prepare to land aboard the aircraft carrier USS George H.W. Bush. Wikimedia Commons/Public domain