In one of his last published essays, written in 1798, the philosopher Immanuel Kant reflected on the impact of the continuing revolution in France. Kant himself was no Jacobin, and opposed extra-legal change as a matter of principle. He conceded that the future course of the revolution's pursuit of liberty and equality "may be so filled with misery and atrocities that no right-thinking person would ever decide to make the same experiment again, at such a price". Regardless of its immediate political consequences, however, Kant could at least see that the universal "sympathy bordering on enthusiasm" solicited by the spectacle of the revolution was itself a telling indication of its eventual significance. Whatever might happen next, the event was already "too intimately interwoven with the interests of humanity and too widespread in its influence upon all parts of the world for nations not to be reminded of it when favourable circumstances present themselves, and to rise up and make renewed attempts of the same kind".

A similar interweaving has characterised sympathetic observation of today's north African revolutions from the moment they began. Of course, it is too early to say what the immediate outcome of Egypt's ongoing mobilisation will be. Anti-government protestors have so far retained the initiative and determined the course and pace of political change. At this point, after a couple of exhausting weeks, Egypt's rulers (both at home and abroad) clearly hope that belated recourse to a familiar mix of divide-and-rule manoeuvrings – minor concessions, secret negotiations, delayed investigations, selective intimidation – may yet manage to distract some of the participants in a mobilisation thus far remarkable for its discipline, unity and resolve. Some observers, who are perhaps themselves exhausted, have begun to wonder whether the spectacle of Egypt's protests might now start to fade away.

Judging from the response in and around Tahrir Square, this seems very unlikely. In a sense, though, what happens in the immediate future may prove less important than what has already happened in the immediate past. Hosni Mubarak and Omar Suleiman already belong to a decidedly ancien régime. The fate of Egypt's revolution is already independent of the next twist in negotiations with the old dictatorship, or the next fumbled response from its American backers.

For whatever happens next, Egypt's mobilisation will remain a revolution of world-historical significance because its actors have repeatedly demonstrated an extraordinary capacity to defy the bounds of political possibility, and to do this on the basis of their own enthusiasm and commitment. They have arranged mass protests in the absence of any formal organisation, and have sustained them in the face of murderous intimidation. In a single, decisive afternoon they overcame Mubarak's riot police and have since held their ground against his informers and thugs. They have resisted all attempts to misrepresent or criminalise their mobilisation. They have expanded their ranks to include millions of people from almost every sector of society. They have invented unprecedented forms of mass association and assembly, in which they can debate far-reaching questions about popular sovereignty, class polarisation and social justice.

Every step of the way, the basic fact of the uprising has become more obvious and more explicit: with each new confrontation, the protestors have realised, and demonstrated, that they are more powerful than their oppressors. When they are prepared to act in sufficient numbers with sufficient determination, the people have proved that there's no stopping them.

Again and again, elated protestors have marvelled at the sudden discovery of their own power. "We look like people who've woken up from a spell, a nightmare," observed writer Ahdaf Soueif, and "we revel in the inclusiveness" of the struggle. Protestor after protestor has insisted on a transformative liberation from fear. "People have changed," teacher Ahmad Mahmoud told a Guardian reporter:

"They were scared. They are no longer scared ... When we stopped being afraid we knew we would win. We will not again allow ourselves to be scared of a government. This is the revolution in our country, the revolution in our minds. Mubarak can stay for days or weeks but he cannot change that."

Such liberation and exhilaration seemed unimaginable just a few weeks ago, in ancien régime Egypt. It is now the people, not the régime, who will decide on the limits separating the possible from the impossible.

This is the main reason why, regardless of what happens in the short term, the long-term consequences of 25 January 2011 may well counter and exceed those of 11 September 2001. Even now, George W Bush and Tony Blair continue to invoke 9/11 as the inauguration of a "new era", as their occasion for "thinking the unthinkable" on a wide range of fronts. In reality, of course, 9/11 was invoked only to justify the implementation of long-standing imperial plans; it served only to consolidate the old balance of power and to intensify an old set of neoliberal trends.

Egypt's revolution raises the prospect of a break with these trends. No one can predict the immediate sequence of events, but it is now possible to anticipate an Egypt that chooses to confront, rather than enhance social inequalities, one that prioritises the interests of the many over the privileges of the few. It's possible to envisage an Egypt that seeks to free itself of foreign influence, and thus an Egypt more willing to recognise the difference between a "peace process" and a "surrender process" in the Middle East. It's possible to imagine a scenario in which Egypt's neighbours might follow suit. It's possible to imagine, in short, how the north African revolutions of 2011 might change the world as a whole.

A future possibility is just that, a possibility. But in Egypt, the present fact remains: for the first time in decades, the decision to determine and then realise such possibilities depends first and foremost on the people themselves.