Carrie Lam Warns She Won't Rule Out China Intervention In Hong Kong

Carrie Lam, Hong Kong's leader, warns of potential Chinese military intervention if protests worsen, though she prefers local solutions. Despite not planning to use emergency powers, Lam recently banned masks using an old law, sparking violence. The protests led to metro shutdowns and injuries, including a 14-year-old shot by police. Thousands of Chinese troops are stationed in Hong Kong, but need local permission to intervene. China could declare a state of emergency to take control, but Lam hasn't specified conditions for seeking mainland help.

What could China do to bypass the constitutional requirement for military intervention?

What was the condition mentioned by Carrie Lam for seeking help from the mainland?