Taiwan's Mainland Affairs Council warns that China's new "ethnic unity" law creates fresh legal danger for Taiwanese companies operating on the mainland — bad news for anyone with money or staff in China.

• Rivals in China can now report Taiwanese business owners as pro-independence to knock out competition.
• The law ties "national unification" to a legal duty, turning a political stance into something you can be punished for.
• Vague wording is the point — it pushes scholars, business people and visitors to censor themselves out of fear.
• Companies are also being forced to split their supply chains into China-linked and non-China ones, which costs real money.
• The push comes as China struggles with a weak property market, high youth unemployment and shaky consumer confidence.

Outlook: Expect more legal pressure from Beijing and more Taiwanese firms rethinking how much they keep exposed to the mainland.