China employing 'gray zone tactics' at contested Second Thomas Shoal, Lowy Institute's Yaacob says

China is employing "gray zone tactics" against the Philippines at the contested Second Thomas Shoal reef, a move likely aimed at avoiding U.S. intervention in the region, according to Lowy Institute's Rahman Yaacob. 

Last week, Philippine officials said Chinese forcesdamaged the country's boats and injured several sailors near the Second Thomas Shoal — claimed by both Beijing and Manila — in the Spratly Islands of the South China Sea. 

Speaking to CNBC's "Squawk Box Asia" on Monday, Yaacob, Southeast Asia Program research fellow at the Lowy Institute, said that while China was testing its boundaries at the Shoal, it has strategically avoided triggering a wider conflict despite the latest escalation. 

"The Chinese, they are experts at operating just below conventional warfare; They are good at employing gray zone tactics against their opponents," he said, adding that the incident was unlikely to trigger an existing defense pact between the U.S. and the Philippines. 

Gray zone tactics refer to "coercive actions that are shy of armed conflict but beyond normal diplomatic, economic, and other activities," according to Rand Corporation.

In 2020, Chinese soldiers engaged in a border clash with India in a disputed region of the Himalayas. While 20 Indian soldiers were killed, weapons were not fired, and it did not escalate into a direct military conflict, Yaacob pointed out.  

Philippine officials have so far avoided invoking the mutual defense treaty with the U.S. even as they have decried Chinese ships' "illegal and aggressive actions" of disrupting its resupply missions to the Shoal.

"But, I suspect if the Chinese use kinetic force, like firing missiles or using guns against Philippine military forces, this may actually trigger the