In Popular Protests, Not the first time: President Obama finds himself in a similar situation to that of Jimmy Carter during the hostage crisis, I outline with a Cambridge colleague James Roslington the historical parallels between the recent spate of anti-US violence and Embassy attacks with the events of 1979.Not for the first time, Western governments have been caught off-guard by a wave of popular protest in Muslim countries. Things started in Cairo with a grassroots assault on the US embassy. Then, in Libya, the attack on the US Mission in Benghazi on September 11, 2012, left four diplomats dead - including Ambassador Christopher Stevens.Another parallel is perhaps more important: the protests and attacks on US embassies in the wake of the Iranian Revolution in 1979. The events in Iran rippled outward because the spread of television sets allowed more people around the world to know what was happening - this parallels the increased access to the internet and social media which have transformed Muslim societies in the last three years. But the current crisis threatens to dash these hopes. Like Ayatollah Khomeini in 1979, leaders of the new Islamist regimes in the region have to cater to the whims of their supporters to preserve their legitimacy. Sooner or later, they may choose to ride the wave of anti-US feeling by caving in to populist gestures - such as permitting the occupation of an American embassy. Like Jimmy Carter, President Obama faces an unenviable choice. Either he can tread carefully, using diplomacy and aid to keep his leverage with the new democracies of the region; or he can court popularity at home by giving in to calls for direct action. The signs are not encouraging.The Republican challenger Mitt Romney has already denounced Obama for his "weak" response. Congressmen have called for the cancellation of US aid to Egypt and Libya. Obama has now ordered very public deployments of warships off the Libyan coast and US Marines to Yemen. Meanwhile, although more diplomatic and humanitarian engagement is needed, the State Department has called on all US citizens to leave Tunisia and Sudan. We can only hope that, despite the pressures of an election year, President Obama will recognise that the long-term interests of the US lie in building constructive relations with the new democracies of North Africa. Knee-jerk reactions such as withdrawing US citizens, or lashing out in revenge, would threaten to undermine all the positive potential that the Arab Spring holds for changing the US position in the Middle East.