China will retaliate. China sends naval escorts with its fishing fleet when it goes to Indonesia and countries fear this happening. Chinaa is not shy of threatening economic sanctions either.
Sending the Chinese Navy into territorial waters off of South America to secure theft of Argentinian natural resources would be a completely different move, and arguably an act of war.
Unfortunate that it's literally called The South China Sea. This dispute will likely never go away.
Even China would not bother.