For the second time this month, a Navy warship conducted a freedom of navigation operation in the South China Sea designed to push back against expansive Chinese maritime claims to the waterway.
The guided-missile destroyer USS Preble sailed within 12 nautical miles of the disputed Scarborough Reef on Monday, said Lt. Cmdr. Tim Gorman, spokesman for the U.S. Pacific Fleet.
China denounced the latest action and said its military forces were dispatched to identify the ship and warn the destroyer to leave the area.
Gorman said the Preble's passage was designed "to challenge excessive maritime claims and preserve access to the waterways as governed by international law."
"U.S. Forces operate in the Indo-Pacific region on a daily basis, including in the South China Sea," Gorman said in a statement. "All operations are designed in accordance with international law and demonstrate that the United States will fly, sail and operate wherever international law allows. That is true in the South China Sea as in other places around the globe."
The spokesman said such freedom of navigation operations "are not about any one country, nor are they about making political statements."
However, the latest ship passage appears to be part of stepped-up military operations designed to counter China's expansive and illegal claims to own disputed islands throughout the sea.
The Permanent Court of Arbitration ruled in July 2016 that China's claim to own some 90 percent of the South China Sea under a so-called Nine-Dash Line was illegal. The court ruled in favor of Philippines in stating there is no evidence China historically exercised exclusive control over the sea or its resources.
"The Tribunal concluded that there was no legal basis for China to claim historic rights to resources within the sea areas falling within the 'nine-dash line,'" the court said.
Scarborough Reef is claimed by China, Philippines, and Taiwan and is located in the Spratly Islands.
Monday's operation was the second time this month the Preble conducted a challenging maritime passage.
On May 6, the USS Preble and another guided missile destroyer, USS Chung Hoon sailed within 12 nautical miles of the Gaven and Johnson Reefs.
Randy Schriver, assistant defense secretary for Indo-Pacific security affairs, said earlier this month China's militarization of disputed islands in the South China Sea are calculated to seek control over the waterway.
China seeks "to operationalize an illegal expansive sovereignty claim; basically everything inside the Nine-Dash Line, or the entire South China Sea," Schriver said.
"So what we'd do about it is we fly, sail, and operate where international law allows, we're increasingly joined by other countries, to make sure that no one country can change international law and international norms, that that water remains international water," he said. "In other words, making that investment that the Chinese have made as insignificant as possible, particularly where their core goal is aimed at."
Schriver said China's activities have been destabilizing for the region. "In response, they're getting more action from the United States—freedom of navigation, presence operations—joined by more and more countries in terms of presence, operations, and activities in the South China Sea, more and more capable maritime Asian nations to deal with maritime security," he said.
Schriver also issued a warning: "And if they continue, potentially more cost imposition."
China was disinvited from sending naval forces to take part in the international Rim of the Pacific, or RIMPAC, war games as a result of Chinese activities in the South China Sea. And there could be more cost imposition in the future, he said.
U.S. pressure in the sea has prevented China from changing the nature of the South China. "China has changed some facts on the ground with respect to the land reclamation and the infrastructure on these outposts," Schriver said. "But the effect that the Chinese seek, which is operationalizing this illegal expansive sovereignty claim, has not been achieved."
U.S. nuclear-capable bombers also have flown missions over the South China Sea and Navy aircraft carriers have sailed in sea in groups and singly in recent months. Navy warships also have stepped up operations in the Taiwan Strait, the 100-mile-wide waterway separating the democratic-ruled island from the communist-ruled mainland.
China has reclaimed an estimated 3,200 acres of islands during the Obama administration that conducted few Navy freedom of navigation operations to avoid upsetting Beijing. In 2015, then-President Obama extracted a pledge from Chinese President Xi Jinping that China would not militarize the disputed islands.
However, the pledge was violated and by April 2018, China had deployed advanced anti-aircraft missiles and anti-ship missiles, along with electronic warfare equipment on several of the islands.
The stepped up naval passages come as China is increasing its fishing activities in the sea.
The Asia Maritime Transparency Initiative reported Monday that Chinese clam harvesting fleets have returned to the South China Sea "in force," including at Scarborough Reef, after a sharp decline in activity from 2016 to 2018. Coral near Scarborough Reef suffered extensive damage from Chinese clamming in 2016, the initiative said.
"These fleets, which typically include dozens of small fishing vessels accompanied by a handful of larger motherships, destroy vast swaths of coral reef in order to extract endangered giant clams," the initiative said.
In contrast to Schriver's remarks, Adm. John Richardson, chief of naval operations, last week sought to play down the Navy's role pressuring China, asserting Navy warship passages have not been increased.
"I've done the analysis so that I can state with confidence that our level of operations, our presence there, has been consistent over the decades," Richardson said last week at a security conference in Singapore. "There's nothing that has spiked recently."
Freedom of navigation passages "are by design non-provocative, non-escalatory. They're just challenging excessive maritime claims in a very consistent basis," Richardson said.
In Beijing, a Foreign Ministry spokesman, said the Preble's passage was a military provocation and that the warship "trespassed … without permission from the Chinese government."
"The Chinese Navy identified and verified the U.S. warship according to law, and warned it off," Lu Kang told reporters. "I have to stress again that the trespass of U.S. warship is a violation of China's sovereignty. It undermines peace, security and good order in the relevant waters. China firmly opposes such move."
The spokesman said China respects freedom of navigation but is "firmly opposed to actions that undermine its sovereignty and security of China under the pretext of freedom of navigation and overflight."
"In disregard of the regional countries' shared aspiration for peace and stability in the South China Sea, the U.S. has been disrupting regional peace and stability time and again under the pretext of 'freedom of navigation and overflight.' Such action is unpopular. We strongly urge the U.S. to stop such provocation lest it should harm China-U.S. relations and regional peace and stability. China will continue to take all necessary measures to defend national sovereignty and security, and safeguard peace and stability in the South China Sea."