Some ideas never go out of fashion, no matter how unfounded they are. One such idea is the belief that America’s large-deck, nuclear-powered aircraft carriers are vulnerable to attack by [insert latest threat here].

We’ve heard this idea over and over again for decades, even though the Chief of Naval Operations opined last year that his carriers are probably less vulnerable today than at any time since World War Two.

The good news is that planners in the Office of the Secretary of Defense have recently begun to back away from the notion that threats to the carrier force are a compelling reason to change the way the Navy is organized.

The bad news is that some analysts around Secretary of Defense Mark Esper still want a “lighter” Navy consisting of lots of smaller surface combatants, some unmanned, and fewer behemoths like carriers.

So as Mike Fabey reported in Jane’s Navy International on May 19, Esper aides are cooking up plans to reduce the number of carriers by stretching out their midlife refuelings, leaving only ten available rather than the minimum of eleven mandated by Congress and the twelve that the Navy has repeatedly said it needs.

Twelve is the lowest number that would allow the Navy to keep 3-4 carriers forward deployed in places like the Western Pacific and the Persian Gulf.

The nicest thing that can be said about this latest effort to circumvent congressional intent is that it is more honest concerning the rationale for reducing the number of available carriers. The driving concern isn’t carrier vulnerability, it’s a desire to free up money for other things—including a dubious project to develop a large unmanned (robotic) warship.

Nonetheless, as these plans advance, we can expect another surge in media commentary about the danger that China poses to our carriers—China being the main focus of current U.S. military strategy.

Before we go down that road, it is helpful to review (1) why the threat posed to our carriers by China isn’t as onerous as feared, and (2) what capabilities the joint force would be losing by shrinking the carrier fleet. I will discuss those topics under the headings of vulnerability and versatility.

Vulnerability. The Navy’s large-deck, nuclear-powered aircraft carriers are the biggest warships ever built—a thousand feet long, 25 stories high, with over four acres of space on the flight deck. This has led some pundits to presume the carriers can be easily tracked and targeted.

In fact, the precise opposite is true. U.S. carriers never stop moving when conducting air operations, and the unlimited range afforded by nuclear power means even China would have great difficulty finding them.

After all, the Western Pacific is a mighty big place. The only practical way to continuously track carrier movements in the Pacific is from orbit, and if the goal is to actually attack the carriers, then Beijing would need over a hundred costly satellites in low earth orbit synchronized with long-range anti-ship weapons and an agile command system.

Beijing doesn’t have those things today and won’t anytime soon. It hardly matters, since U.S. war plans call for preempting such systems before they can go into action. So don’t take all those stories about China’s carrier-killing missiles too seriously, because the missiles are useless if the target can’t be found.

Finding the target is actually just the first step in a complex “kill chain” that Chinese forces would need to execute. Once a carrier is found, its location needs to be fixed; the carrier needs to be tracked; it needs to be targeted by one or more weapons that are within range and sufficiently powerful to disable that carrier; the carrier needs to be engaged; and defenders must then assess the success of their actions.

If this kill chain is disrupted at any point in its sequence of tasks, the whole process breaks down. Navy planners are confident they can do that, relying on a layered defense that includes the carrier’s air wing, networked escort vessels hosting the world’s most advanced air defense system, a redundant overhead reconnaissance capability and the carrier’s own onboard defenses.

At 35 miles per hour, U.S carriers can outrun submarines and disappear into thousands of square miles of ocean within minutes. If by some miracle a Chinese submarine happens to stumble across a U.S. carrier, its probability of sinking the carrier would be close to zero. With hundreds of watertight compartments and extensive armoring, torpedoes would have only modest effect. But chances are the sub would never get into firing position anyway, given the anti-submarine systems typically resident in a carrier strike group.

Versatility. So reports of carrier vulnerability are greatly exaggerated. But when it comes to capability, large-deck, nuclear-powered carriers of the type the U.S. Navy operates are uniquely versatile.

For starters, aircraft carriers provide forward basing for up to 90 aircraft, without requiring access to bases in other countries. They can be maneuvered quickly into the most advantageous operating locations, because they are the fastest large surface vessels in the world.

Thus deployed, the strike aircraft in the carrier’s air wing can destroy hundreds of targets at sea or ashore every day using precision-guided weapons (“smart bombs”). Meanwhile, other planes in the strike group can jam the radar and communications of enemy forces, and provide airborne surveillance to all joint assets operating in a war zone.

The air wing can be used flexibly to conduct long-range strike operations, perform sea control that sweeps enemy warships from large areas, or provide continuous air cover to friendly forces ashore. Because the carrier is not dependent on the land bases of other nations and can move fast, it is well suited to both rapid response in crises and deterrence of potential aggressors.

No other country in the world has a force remotely approaching the warfighting utility and flexibility of U.S. large-deck, nuclear-powered aircraft carriers. They enable missions that would be impossible to accomplish using other means. And contrary to popular misconception, they are less vulnerable than any other vessel on the ocean’s surface.

Let’s try to keep some of these details in mind as Washington approaches yet another debate on what its future Navy should look like.