Seperate thread for Max Visibility.

Coast guards around the world are often overlooked. Their missions  —  law enforcement and search and rescue  —  make them perhaps less bellicose than navies, although coast guards are often formal military branches in their own right, as in the United States.

China's coast guard is more muscular than most. Even combative. And China's coast guard has one especially combative ship  —  the CCG3210, formerly known as the Yuzheng 310.

CCG3210 has influenced politics in the South China Sea, of which China lays claim to virtually the entire territory. In a recent example from May, the Indonesian destroyer Oswald Siahaan-354 shelled the stern of a Chinese fishing trawler intruding in Indonesian waters near the Natuna Islands.

That Indonesia found it appropriate to deploy a heavily-armed destroyer to intercept a fishing boat is partly because of a more aggressive approach by Jakarta to counter Chinese intrusions. And it may be because of repeated close encounters with CCG3210, a 2,580-ton Chinese coast guard patrol ship armed with machine guns, light cannons, and (likely) advanced hardware capable of jamming communications.

China has installed equipment on two of its fortified outposts in the Spratly Islands capable of jamming communications and radar systems, a significant step in its creeping militarization of the South China Sea, U.S. officials say.

The move strengthens China’s ability to assert its extensive territorial claims and hinder U.S. military operations in a contested region that includes some of the world’s busiest shipping routes.

The disclosure comes as the Chinese military is conducting what U.S. officials describe as its largest military exercise to date in the South China Sea, maneuvers that include China’s first aircraft carrier as well as air force and ground units.

A U.S. Defense Department official, describing the finding, said: “China has deployed military jamming equipment to its Spratly Island outposts.”

The U.S. assessment is supported by a photo taken last month by the commercial satellite company DigitalGlobe and provided to The Wall Street Journal. It shows a suspected jammer system with its antenna extended on Mischief Reef, one of seven Spratly outcrops where China has built fortified artificial islands since 2014, moving sand onto rocks and reefs and paving them over with concrete.

In the wake of Russia's demonstrations of advanced electromagnetic spectrum and communications jamming capabilities, most recently displayed in their incursion into Ukraine, China also is upping its game in this space, demonstrating similar capabilities in the Pacific.

The U.S. Department of Defense, in an annual report to Congress on China’s military and security developments, assessed that the country is placing greater importance upon EW, on par with traditional domains of warfare such as air, ground and maritime.

"The [People’s Liberation Army] sees EW as an important force multiplier, and would likely employ it in support of all combat arms and services during a conflict," the 2016 report asserts. "The PLA’s EW units have conducted jamming and anti-jamming operations, testing the military’s understanding of EW weapons, equipment, and performance. This helped improve the military’s confidence in conducting force-on-force, real-equipment confrontation operations in simulated EW environments."