A few days ago, USS Decatur, a guided missile destroyer of the US Navy, intruded into the territorial sea of China's Xisha Islands (Paracel Islands). China responded by dispatching two ships and a JH-7 fighter-bomber to expel the US vessel from the waters.

Why did the United States' military vessel enter the South China Sea?

The US' intention was to challenge China's maritime claims in the South China Sea, as it claimed the baselines of Chinese territorial sea were unlawful. The US claim is baseless.