As anti-regime protests rage across Iran and US warnings intensify, the spotlight is firmly on the country's most powerful figure-Supreme Leader Ayatollah Ali Khamenei. With President Donald Trump putting Tehran on notice and several countries issuing safety advisories to their citizens, questions are mounting over Khamenei's visibility and grip on power. Iran has accused Washington of pursuing regime change, even as global attention turns to the US's next move amid a rapidly escalating crisis.