The United States, Russia, and China all tested new super-fast “hypersonic” munitions in 2018, escalating a global competition for weaponry that can strike farther and harder than ever before and potentially defeat existing defenses.

The Russian and Chinese hypersonics tests were the most dramatic. But the much quieter American trial pointed toward a much more immediate and widespread transformation of military capabilities than the Russians or Chinese are likely to achieve.

The world's armies have long eyed faster munitions, especially faster munitions that also are maneuverable. Swifter, nimbler rockets could strike with less warning and evade missile-defense systems. Speedier, more streamlined artillery shells could travel farther and impact with greater destructive force.

Most experts agree: If a weapon can travel at least five times the speed of sound, it's hypersonic—although some say the munition must be maneuverable, too, to be effective.

In late December, Russian President Vladimir Putin announced that the Kremlin had tested the new Avangard hypersonic rocket. "The test was completely successful," Putin said. "All technical parameters were verified."

Avangard is a hypersonic glide vehicle. It boosts into the upper atmosphere atop a rocket then detaches and glides toward its target, performing small maneuvers en route. The Kremlin announced it would fit Avangard with an atomic warhead and, starting in 2019, deploy it alongside old-style intercontinental ballistic missiles.

But as a delivery system for nuclear warheads, Avangard doesn't actually enhance Russia's military arsenal. That's because Russia's ICBMs already possess the range to strike targets all over the world and the speed to evade all but the luckiest shot by American missile defenses.

Indeed, ICBMs in the terminal phase of their flight already are hypersonic. Avangard flies lower in the atmosphere than an ICBM does and might be faster than an ICBM is in early phases of flight. The practical differences end there.

"I don't think this system brings any new capability that the existing weapons like ICBMs don't have," Pavel Podvig, an independent expert on the Russian military, told The Daily Beast.

America's own nukes deter Russia from using its nukes, and vice versa. Labeling a new weapon "hypersonic" doesn't alter that balance of power.

For that reason, the nuclear-armed Avangard mostly is for show. It looks fearsome and sounds cool. "There is a lot of political theater there," Podvig said.

James Acton, a weapons expert at the Carnegie Endowment for International Peace in Washington, D.C., said a nuclear-armed hypersonic weapon is no more threatening than an older ICBM is. "What does concern me is a very long-range conventionally-armed system," he added.

Unlike a nuke, a conventional weapon might actually get used in scenarios short of a world-ending apocalypse. "That would pose a real new threat to the United States,” Acton said.

It’s China, not Russia, that's making what seem the biggest strides toward fielding a non-nuclear hypersonic weapon. But even China's new weapon is less fearsome than it might appear to be. Ironically, its own sophistication holds it back.

Around the same time Putin announced the results of the Avangard test, a photo appeared online that showed a Chinese warship sailing the open ocean while armed with an electromagnetic railgun that could be capable of firing shells at hypersonic velocity.

A railgun propels its projectiles by way of magnetic force, as opposed to explosive-powder charges that conventional guns use.

China's railgun first appeared in January 2018 in a photo of the Chinese navy landing vessel Haiyang Shan while the ship reportedly was at a facility in Wuhan on the Yangtze River. A large cannon was visible on Haiyang Shan 's forward deck.

In March, Chinese state media confirmed the cannon was an experimental railgun. The December photo seemed to confirm that the gun had undergone at-sea tests, making it the first such weapon to do so.

The U.S. Navy since 2012 has been developing its own railgun, but as of early 2019 the weapon had yet to go to sea. That doesn't mean the Americans weren't working on super-fast weapons, however.

Pentagon officials in early January leaked news of the U.S. Navy's own hypersonics test, this one involving a Navy warship firing hypersonic shells during a summer 2018 war game near Hawaii. The Pentagon's secretive Strategic Capabilities Office helped to oversee the trial.

In the test, the destroyer USS Dewey fired 20 of the hypervelocity projectiles from its standard, five-inch-diameter gunpowder cannon, officials told the website of the U.S. Naval Institute.

The new projectile is more aerodynamic than old-style shells and features tiny fins and a radar guidance system that helps it to hone in on a target at speeds as fast as seven times the speed of sound. That’s roughly three times the velocity a normal naval shell can achieve.

Far-flying and accurate, the shells in theory can target ships, ground targets, aircraft and even incoming missiles.

At first glance, the American test might appear to be the least remarkable of the three countries' 2018 hypersonics trials. It didn't involve a new gun or missile, just a new, super-aerodynamic shell. The shell is non-nuclear. The Pentagon didn't formally announce the test or circulate any photos.

But the U.S. test arguably is the most likely to result in the widespread deployment of a truly transformational new weapon. And it underlines the Pentagon's advantage over the Russian and Chinese militaries in the hypersonics race.

While Russia, China and the United States all are developing a wide array of new hypersonic weapons, it’s telling which systems each country has prioritized.

Russia has focused on seemingly impressive but marginally useful hypersonic weapons that make for good PR but don’t actually shift the balance of power. China for its part has chosen to tinker with very advanced high technology that might prove impractical. America meanwhile has focused on less sophisticated weapons it’s reasonably certain it can deploy quickly and widely, while deferring development of more ambitious munitions designs until the technology is more mature.

"Experts often argue the United States is behind in this technology because Russia and China appear to be testing more frequently," Acton wrote in an explainer on the Carnegie Endowment website. "This is true, but in many ways, the United States is running a different race from Russia and China."

Usefulness and scalability are the American weapon's major advantages over the Russian and Chinese weapons. In opting to develop a unique, electromagnetic cannon to fire super-fast projectiles, China has limited how fast it can deploy its new hypersonic weapon.

To re-equip with hypersonic munitions, Beijing will need to build expensive new guns for its ships and artillery units. Washington's forces, by contrast, simply can arm thousands of existing sea- and land-based powder guns with the new hypersonic shell.

That was a deliberate choice on the Americans' part. In 2016, Robert Work, the Obama administration's deputy secretary of defense, advised the incoming Trump administration to consider investing in hypervelocity projectiles rather than in railguns.

“We thought railguns were something we were really going to go after, but it turns out that powder guns firing the same hypervelocity projectiles gets you almost as much as you would get out of the electromagnetic rail gun, but it’s something we can do much faster," Work said.

"We now think that we can do pretty revolutionary things with existing powder guns—think howitzers, [U.S. Army] Paladin [artillery systems], the Navy’s five-inch guns," William Roper, then the head of the Strategic Capabilities Office, said in 2016. "We’ve shifted emphasis to that."

“We have a thousand powder guns," Roper added. "We have very few railguns."

Russia and China with their showy demonstrations and bespoke technology might appear to have pulled ahead in the early laps of the race for hypersonic weapons. But the United States, with its emphasis on a weapon that it can deploy quickly and actually use in a non-nuclear war, ultimately could gain the military advantage.