Leading article: Now the Egyptian military must hand power to the people

The euphoria on the streets of Cairo last night said almost everything that needed to be said about the end of President Hosni Mubarak's rule.

After 18 days of determined and peaceful protest, the people of Egypt had reaped their reward. The fury and disappointment of the previous evening, when Mr Mubarak made his last, desperate, claim to stay in power, were forgotten in the few moments it took the vice-president, Omar Suleiman, to make his televised statement. The President had resigned and handed control of the country to the Supreme Military Council of the Armed Forces. There was laughter, tears, jubilant waving of flags, hooting of horns and collective embrace of a victory well won.

Rightly, the day belonged to the protesters, who had spearheaded what became a popular uprising against three decades of increasingly malign dictatorship. Admirable and impressive though the joy was, and the upsurge of patriotic pride it denoted, it does little to dispel the uncertainty that has swept the region since the crowds, inspired by the toppling of president Ben Ali in Tunisia, first came out on to the streets. And that uncertainty begins with the role of the Egyptian army. Under other circumstances, a presidential resignation in favour of the military would be seen as an old-fashioned coup d'état. Everything now depends on how the military uses its power.

As the celebrations showed yesterday, it starts on the most positive footing possible. Through the protests, the armed forces maintained the role of honest broker, refusing to use force to bolster Mr Mubarak or even to intervene. From then on, the temporising that seemed to characterise its initial approach ceased to be an option.

In many ways, it is a sad comment on the configuration of power in Egypt that the start of the post-Mubarak era was always likely to depend at least as much on the military as on the people. But that is a reflection partly of history, and partly of the massive assistance Egypt's armed forces have received over 30 years from the United States. With hindsight, many will detect Washington's hand behind aspects of the army's comportment during this crisis. Did the US, as has been rumoured, warn Egypt's top brass against turning guns on the protesters because it feared the backlash if weapons "made in the USA" were used in this way? Whatever the truth, one consequence of the military's dominance is that Egypt's other state institutions were left pitifully weak – and this risks complicating any transition.

At best, the Supreme Military Council which is now entrusted with power will be guided by the demands of the protesters for openness and democracy. It should honour its promise to end the state of emergency, defer so far as possible to civilian ministers, and preside over a swift move to elected government. Unfortunately, precedent suggests that mighty military establishments can be just as reluctant to cede power as undemocratic presidents.

But this is where the US and Europe can make their contribution. There is now not the slightest ambiguity about the direction in which Egyptians want to go. People power has prevailed; the call is for freedom, fair elections and democratic government. All those outside Egypt who cheered Cairo's protesters on have a duty to ensure that those who now hold the reins of power do not betray those expectations.