Twenty years after the “one party, two systems” treaty guaranteed Hong Kongers’ democratic rights, we ask if China has kept its promises and whether the UK should have been a better advocate for its former colony. We get the verdicts from Lord Patten, the last British governor of Hong Kong; Carrie Lam, Hong Kong’s chief executive; Nathan Law, one of the key figures of the Umbrella Movement and the youngest lawmaker in Hong Kong’s history; and China Dialogue’s Isabel Hilton.