Unpredictable Trump weighs up Iranian pleas for help against calls for restraint

Observers say if US gets response wrong to Tehran's repression it could end up entrenching regime's position

• Iran warns US against attack as protest death toll reportedly soars

Donald Trump is being warned by Iranians that it will be too late unless he acts quickly to fulfil his promise to help protesters under fire from security services in Iran but the president is receiving conflicting advice about the potential effectiveness of a US intervention.

A major intervention by Washington, some are warning, will only fuel the fire of an Iranian government narrative that the protests are being manipulated as part of an anti-Islamic plot being led by the US and Israel.