Key point: In an actual war, both Washington and Beijing would employ their conventional missile arsenals to sink each other's ships.

The Chinese military lobbed anti-ship ballistic missiles into the South China Sea in tests in early July 2019.

The missile trials underscored Beijing’s increasing militarization of resource-rich waters on which several countries have conflicting claims.

“The Chinese carried out the first test over the weekend, firing off at least one missile into the sea,” NBC News reported on July 1, 2019, citing a U.S. official with knowledge of the test.

“The window for testing remains open until July 3, and the official expects the Chinese military to test again before it closes.”

No U.S. Navy vessels were in the area when the missile or missiles splashed down, NBC News reported. Still, the official described the event as "concerning."

China in recent years has occupied several disputed islands in the China Seas, dredged their endangered coral reefs and built atop them sprawling airfields and barracks and installations for cruise missiles and air-defense systems.

The U.S. Navy frequently sails warships through international waters near these fortified islands in order to assert its rights to navigate open waters. These "freedom-of-navigation operations," or FONOPs, often draw harsh condemnation from Beijing.

In January 2019 China deployed anti-ship ballistic missiles to the country's northwest plateau in an apparent attempt to protect them from the U.S. Navy's own missiles.

The People's Liberation Army Rocket Force positioned at least a dozen transporter-erector-launcher vehicles for the DF-26 anti-ship ballistic missile at a previously undisclosed training range near Alxa in China's Inner Mongolia region, Jane's reported after reviewing DigitalGlobe satellite imagery dated Jan. 9, 2019.

The deployment reportedly was a response to the appearance of a U.S. Navy warship near the Paracel Islands on Jan. 7, 2019. The destroyer USS McCampbell sailed near the island group as part of a FONOP.

China, Vietnam and Taiwan all claim the Paracels, which lie around 650 miles from China's Hainan Island. In recent years China has dredged several reefs in the Paracels and built military outposts on them.

China's state-run Global Times new outlet described McCampbell's appearance near the Paracels as "trespass."

"McCampbell sailed within 12 nautical miles of the Paracel Islands to challenge excessive maritime claims and preserve access to the waterways as governed by international law,” Lt. Rachel McMarr, a U.S. Pacific Fleet spokesperson, told the news website of the U.S. Naval Institute.

The DF-26 is China's most powerful anti-ship missile. It's 46 feet tall and weighs 44,000 pounds. "The DF-26 comes with a 'modular design,' meaning that the launch vehicle can accommodate two types of nuclear warheads and several types of conventional warheads," the Center for Strategic and International Studies in Washington, D.C. reported.

With a range of up to 2,500 miles and 4,000-pound payload, with satellite targeting the DF-26 in theory could strike U.S. Navy warships across the western Pacific Ocean. "Even when launched from deeper inland areas of China, the DF-26 has a range far-reaching enough to cover the South China Sea," an unnamed military expert told Global Times.

The DF-26 could be vulnerable to the latest American defenses. The U.S. Navy's SM-6 interceptor missile theoretically is capable of hitting a DF-26 in two phases of its flight -- shortly after launch, as the Chinese missile is climbing and gaining speed, and then again in the DF-26's terminal phase, as it arcs down toward its target.

The missile, which arms U.S. Navy cruisers and destroyers, completed three successful test interceptions in 2015, 2016 and 2017, according to the U.S. Missile Defense Agency.

In moving a dozen DF-26 launchers to Inner Mongolia, around 2,000 miles from the Paracels, China reportedly aims to protect the rockets from boost-phase interception. "A mobile missile launch from deep in the country's interior is more difficult to intercept," Global Times paraphrased a Beijing-based military expert as saying.

The SM-6 can travel no farther than a few hundred miles. If China attacked an American warship from a missile base in Mongolia, the American ship's only chance of hitting the rocket would be during the final seconds of its flight.

An expert told Global Times a terminal interception is more difficult than a boost-phase interception would be. "After the missile enters a later stage, its speed is so high that chances for interception are significantly lower."

Even if the Americans can't shoot down the DF-26, it's unclear that the rocket reliably could hit a moving ship at sea from 2,000 miles away. "The accuracy of the DF-26 is uncertain," CSIS explained, "with speculators estimating the [circular error probability] at intermediate range between 150 to 450 meters," or around 500 to 1,500 feet.

In any event, China has prepared its missile base near Alxa for many more missiles. "It features a garrison complex, a probable missile storage and handling facility and over 100 prepared launch positions," Jane's reported.

The Alxa base is outside the range of detection by U.S. radars in the region, the Hong Kong South China Morning Post pointed out.

It’s unclear whether the missiles in China’s July 2019 tests in the South China Sea launched from Alxa. Regardless, the trials highlighted Beijing’s growing military strength, and resolve, in the South China Sea.

“China does need to have necessary defense of these islands and rocks which we believe are Chinese territory," high-ranking Chinese officer Zhou Bo told CNBC in June 2019.

David Axe serves as Defense Editor of the National Interest. He is the author of the graphic novels  War Fix, War Is Boring and Machete Squad. This first appeared in July 2019.

Image: Reuters.