Just a day after the Chinese military conducted a missile test in the South China Sea, the United States Navy's guided-missile destroyer conducted a freedom of navigation operation (FONOP) past the disputed Paracel Islands, which are claimed by China as well as Vietnam and Taiwan. The USS Mustin (DDG-89) operated past the islands, the U.S. Seventh Fleet announced on Thursday.

"This freedom of navigation upheld the rights, freedoms, and lawful uses of the sea recognized in international law by challenging the unlawful restrictions on innocent passage imposed by China, Taiwan and Vietnam and also by challenging China's claim to straight baselines enclosing the Paracel Islands," Cmdr. Reann Mommsen told USNI News.

China has several installations on the island chain that is east of the coast of Vietnam, and Beijing claims a zone around the chain and requires that foreign warships seek permission to enter the area.

"All three claimants require either permission or advance notification before a military vessel or warship engages in 'innocent passage' through the territorial sea," read a statement from the U.S. Navy.

"The unilateral imposition of any authorization or advance-notification requirement for innocent passage is not permitted by international law. By engaging in innocent passage without giving prior notification to or asking permission from any of the claimants, the United States challenged the unlawful restrictions imposed by China, Taiwan and Vietnam."

Beyond Disputed Waters

The deployment of the U.S. Navy's USS Mustin to the area also followed a Chinese missile launch with the weapons coming down near the disputed islands. Multiple sources reported that the missiles launched by China on Wednesday included the DF-21D and DF-26B – weapons that are believed to central to Beijing's strategy of deterrence in the region.

"Such exercises also violate PRC commitments under the 2002 Declaration on the Conduct of Parties in the South China Sea to avoid activities that would complicate or escalate disputes and affect peace and stability," a Pentagon statement said following the launch.

To suggest it was a busy week in this latest tit-for-tat show of force between China and the United States would be a vast understatement. China's test followed the deployment of a U-2 reconnaissance aircraft over a so-called "no-fly zone" in the Bohai Sea, the northwestern and innermost extension of the Yellow Sea. China had maintained that the People's Liberation Army (PLA) had declared the region a no-fly zone as the Chinese military was conducting live-fire military drills in the area.

Beijing labeled the flight "naked provocation" after the spy plane entered the airspace while the People's Liberation Army Navy (PLAN) was conducting exercises.

"The trespass severely affected China's normal exercises and training activities and violated the rules of behavior for air and maritime safety between China and the United States, as well as relevant international practices," Wu Qian, a spokesperson for the Chinese Defense Ministry, said in a statement. "The U.S. action could easily have resulted in misjudgments and even accidents."

Such accidents have occurred with tragic results, unfortunately.

It was nineteen years ago in April 2001, in which a U.S. Navy EP-3 spy plane collided with a Chinese J-10 fighter jet, which resulted in the death of a Chinese People's Liberation Air Force (PLAAF) pilot who was killed and the American plane was forced to make an emergency landing on the island of Hainan. The twenty-four U.S. aircrew members were held for eleven days until Washington was forced to apologize for the incident.

Earlier in the month the USS Mustin had also transited the Taiwan Strait in what the Navy described as "routine" and "in according with international law." The transit of Arleigh Burke-class guided-missile destroyer came after it had conducted joint exercises with Japanese warships in the East China Sea.

It was the 10th transit of the Taiwan Strait this year – and likely won't be the last.

Peter Suciu is a Michigan-based writer who has contributed to more than four dozen magazines, newspapers and websites. He is the author of several books on military headgear including A Gallery of Military Headdress, which is available on Amazon.com.