talk that to US,they just stood by and watched when their treaty ally S.Vietnamese was being attacked by China.
The next day, Chinese jet fighters and ground-attack aircraft from Hainan bombed the three islands, and were followed up with an amphibious landing force. The South Vietnamese Marine garrison was captured, and the naval force retreated to Đà Nẵng.
While the battle was going on, the Vietnamese fleet detected two Chinese reinforcing warships rushing to the area; China later acknowledged that these were the Hainan-Class submarine chasers #281 and #282. Despite reports that at least one Vietnamese craft had been struck by a missile, China insisted that no missile-bearing ships were involved in the battle. In addition, the South Vietnamese fleet also received warnings from the United States that their naval radar had detected additional Chinese guided missile frigates and MiG jet fighters on their way from nearby Hainan. South Vietnam requested assistance from the US Seventh Fleet, but the request was rejected.