As China and the U.S. engage in increasingly frequent contact in the South China Sea, missile technology looks set to play a role in complicating the situation.

According to a new report delivered to the U.S. Congress, Chinese submarines are now carrying advanced missiles which are incredibly dangerous for U.S. ships operating in the region, writes David Tweed for Bloomberg.

Supersonic Anti-Ship Missile Allows China To Threaten U.S. Navy

Supersonic anti-ship missile presents problems for U.S. Navy

Researchers claim that the YJ-18 submarine-launched missile accelerates to supersonic speed immediately before striking its target, which makes it more difficult for sailors to defend their ship. At the same time defense officials from countries throughout Southeast Asia have warned of the increase in “clutter” in the contested waters of the South China Sea as various nations build more submarines.

The U.S. has taken it upon itself to challenge China’s claim to large areas of the South China Sea, and a U.S. warship recently made a patrol inside the 12-nautical mile buffer zone that China claims as sovereign territory around the artificial islands that it has been constructing. The USS Lassen was followed closely by two Chinese ships as it passed by the island.

With a cruising speed of around 600 miles per hour, the YJ-18 moves at just below the speed of sound, skimming a few meters above the waves. According to a report from the U.S.-China Economic and Security Review Commission at around 20 nautical miles from its target it accelerates to as much as three times the speed of sound.

“The supersonic speed makes it harder to hit with on-board guns,” according to Larry Wortzel, a member of the commission. “It also makes it a faster target for radars.”

Freedom of movement could be restricted in South China Sea

The report claims that its speed, range and wide deployment “could have serious implications for the ability of U.S. Navy surface ships to operate freely in the Western Pacific” should there be a conflict with China. The Obama administration showed its lack of respect for Chinese territorial claims by sending the warship so close to the island, which may soon house an airstrip capable of handling every plane in the Chinese military.

Wortzel went on to add that the YJ-18 would be incredibly useful in implementing China’s strategy of keeping enemy forces far away from the coast of the mainland, as well as from waters inside the first island chain. Continued U.S. Navy activity in those waters could lead to increased tensions and could result in skirmishes, said Chinese navy commander Wu Shengli during a conference call with U.S. Chief of Naval Operations John Richardson on Thursday.

The U.S. wants to maintain freedom of navigation in the vital shipping lanes, which handle $5 trillion of international shipping each year. However China believes that over 80% of the sea is its maritime territory, a claim which is disputed by 5 other nations including Vietnam and the Philippines.

Chinese area denial strategy boosted by missile

According to the Office of Naval Intelligence April report, China had started deploying its latest missile. No details were given on its range in that report, but the Commission has now claimed that the YJ-18 can hit a target around 290 nautical miles away. Its predecessor, the YJ-82, had 14 times less range.

“One goal of the Chinese counter-intervention strategy, which we call anti-access/area denial, is to keep opposing forces away from China’s coast and from the waters inside the First Island Chain,” said Wortzel. The missiles would be “particularly helpful in implementing the naval strategy of keeping an opponent outside the range of Tomahawk cruise missiles and carrier-based fighters and away from the Chinese coast.”

Chinese analysts define the First Island Chain as the series of archipelagos that reach from Russia, past Japan and Taiwan, towards the Philippines, Brunei and Malaysia.

China developing dangerous missiles

Despite worries over the YJ-18 missile, the report claims that Chinese command and control infrastructure may not be sufficient to allow Beijing to make full use of its capabilities. In fact Chinese navy forces may not be able to generate enough targeting information to make full use of the missile, while China’s command and control systems could be vulnerable to electromagnetic warfare operations.

Alongside the YJ-18, China has also been developing the so-called DF-21 “carrier killer” ballistic missile. The latter was seen during the huge military parades commemorating victory over Japan during World War 2. The DF-21 would be fired from land-based mobile launchers and target aircraft carriers, while the YJ-18 could slow the progress of a carrier group towards China, said the report.

China appears to be creating the necessary conditions in order to restrict foreign access to waters near to its coast, a scenario that the U.S. cannot abide.