Leading article: A Middle East power in the making

Egypt's President Mohamed Morsi's denunciation on Thursday of the repression of the Syrian uprising was at least as notable for the venue at which he issued it as for its unequivocal content.

Iran had seen the new Islamist President's decision to attend the summit of the Non-Aligned Movement, which it hosted, as something of a triumph. Its hopes – and Western fears – that he would use it to cement a new alliance between Cairo and Tehran have hardly been fulfilled, at least for now.

Instead, the President chose the largest international conference staged in Iran since its 1979 revolution to blame, in terms stark enough to provoke a walkout by Syria's foreign minister, the current bloodshed on the "oppressive regime" which is Iran's closest regional ally, and to identify the original uprising with the one that swept Hosni Mubarak from office in his own country last year.

It does not diminish the significance of the speech to say that it should not have come as a complete surprise. There is an element of realpolitik, of course; Egypt is heavily dependent on aid from Iran's bitterest rival, Saudi Arabia. Egypt's vast Muslim population is overwhelmingly Sunni, like the majority reasserting itself in Syria, but unlike that of Shia Iran. And it would have been incongruous, to say the least, if a Muslim Brotherhood leader had decided not to endorse the uprising against the Assad regime. The influence of its sister organisation inside Syria may have been exaggerated, but it remains an important opposition player.

But Mr Morsi's attack is at the most basic level a salutary reminder of the obsolescence of sweeping generalisations about the "moderates" and what Tony Blair was wont to describe as "the arc of extremism" in the Muslim world. The Egyptian President's definition of his foreign policy is a work in progress. The fact that he has embarrassed Israel's greatest enemy, for example, does not necessarily mean that he will be as emollient towards Israeli interests as Mubarak was. But if nothing else, his intervention on Syria this week demonstrates that Egypt is on the way – and not always predictably – to re-emergence as a serious regional power.