Potential reformer: Iranian opposition leader Mir-Hossein Mousavi 

Each year since the 1979 siege of the American embassy in Tehran, the Islamic Republic has organised orgies of anti-American vitriol — an annual reminder of this regime's deranged foundations. 

Yet on the 30th anniversary in October, thousands of protesters flooded the streets chanting messages of conciliation, not invective. The Opposition leader Mir-Hossein Mousavi urged his supporters to "focus attention on the enemy within, not abroad". The crowds chose to address the President of the US directly, crying: "Obama, either with the murderers or with us." 

The President could have responded with a speech expressing gratitude for the hand of friendship extended to America by the protesters. He has said nothing. 

Although Iran's pro-democracy Green Movement has continued to grow despite the brutal crackdown that followed the protests against June's fraudulent elections, Obama has barely engaged with Iranian dissidents. Surely Washington should jump at the chance to support any challenge to this criminal regime, yet it seems that Obama's vaunted policy of outreach extends to dictators but not to their captive populations.

The administration has deployed a number of facile arguments to defend this reticence, but seems chiefly motivated by a half-baked revival of détente. Spokesmen for the President have also suggested that American support would only undermine the authenticity of the movement, by enabling the regime to paint the protesters as American puppets. 

Neither of these arguments stands up to historical scrutiny. Détente was a boon to the USSR, lending that regime stability by refraining from comment on the Soviet Union's democratic deficit — the great weakness of any dictatorship.