In Egypt this week all eyes are on President Mohammed Morsi and his move in conjunction with other military leaders to replace top leaders of the military establishment.
The jury is still out on the significance of the sudden move by Mr Morsi, who was elected in June as the candidate of the Muslim Brotherhood's political party.
Is this the long-awaited assertion of true civilian control over Egypt's governmental apparatus? Is it simply a reorientation of the relationship between the military and the new president? What implications does this have on the Islamist agenda of the Brotherhood on Egypt?
But the struggle with the military is not the only battlefield in the Brotherhood's muscle-flexing. A look at what's happening in the Sunni religious establishment in Egypt is informative.
First, it is important to understand that contemporary Arab Islamism is not simply a political project. It grows from two distinct trends of religious reformism.
The first of these is referred to as Salafism, a movement begun in the 1700s that is also, pejoratively, referred to as Wahhabism.
The second trend has distinct religious references in the 20th century, with the likes of Mohammed Abduh, Rashid Rida and eventually the Brotherhood.
Supporters of both consider themselves to be Salafis in that they want to return, though in very different ways, to the spirit of the "Salaf", the first generations of Muslims. To distinguish between the two, it is useful to describe the first group as "purist Salafis" and the second as "modernist Salafis".
Saudi financial patronage has helped spread purist Salafism beyond Saudi Arabia, while modernist Salafism has been helped by the Muslim Brotherhood apparatus worldwide.
The overwhelming majority of Sunni Muslims, however, remain attached to mainstream Sunni orthodoxy, represented in Egypt by the Azhar religious and educational establishment.
Al Azhar considers itself, and is recognised by Sunni establishments, to adhere to historically correct Sunni doctrine and practice. That translates into acceptance of the validity of the major rites of Sunni jurisprudence, the main theological approaches, and Islamic mysticism known as Sufism.
Al Azhar has been generally suspicious of the modernist Salafism that shaped the Brotherhood, on account of its politicisation of religion. In Al Azhar's view, modernist Salafi methodology is unsound or weak. And Al Azhar is far more stridently opposed, openly so, of purist Salafism for reasons related to creed, law and spirituality.
When purist Salafism was established, in the 1700s, the Sunni religious establishment of the time saw it as heterodox. Much of Al Azhar still thinks that way.
Most non-Islamist political forces in Egypt have recognised that in a country where religion is so important, Al Azhar is a critical institution. And non-Islamists in politics see Al Azhar as a bulwark against the politicised Brotherhood and puritanical purist Salafis.
This means the Azhari establishment, and non-Islamist political forces, have a shared interest in supporting Al Azhar against Salafi pressure.
So when Islamists joined in declaring that Egypt's "Islamic frame of reference" is Al Azhar, many Egyptians saw that as a positive sign. The non-Islamist political elite thought Salafi zealotry would be tempered by a calmer, scholastic establishment that deemed itself the conscience of the nation, not its chastiser.
But President Morsi's cabinet appointments suggest that this might have been presumptuous. A well-known Salafi announced he had been chosen minister of religious endowment, but was met with loud objections from senior scholars and the office of the Shaykh Al Azhar, head of Al Azhar University.
Al Azhar's concern seems to have been that the Salafis have an agenda to "Salafise" the religious establishment.
Curiously, the government first seemed to have backed down and settled on an Azhari close to the Shaykh Al Azhar's office, but after a last-minute change of heart the post went to Talaat Afify, an Azhari who is also a member of a Salafi charitable organisation.
The Brotherhood, as noted, is not at its core a purist Salafi organisation, but purist Salafism has certainly made inroads into it. Khairat Al Shater, a principal Brotherhood financier sympathetic to purist Salafism, is said to have been behind the nomination of Mr Afify.
The orientation of Al Azhar may have repercussions far beyond Egypt: Al Azhar University is the world's pre-eminent Sunni institution. It is the flagship Sunni educational institution, quite distinct from Saudi universities that promote purist Salafism.
The redirection of Al Azhar, then, would evidently have serious consequences all across the Sunni world. Was the attempted initial appointment an effort to satisfy Mr Morsi's purist Salafi supporters? Was the final appointment a compromise? If so, how much further will Mr Morsi go in Salafising the religious establishment? Will Al Azhar University withstand such pressures? How?
And finally, is it equipped to maintain its current official creed and simultaneously increase its independence from the state, calling its institutions and leaders to account when necessary?
The answers to these questions have ramifications not simply for Egypt but for Sunni Muslims worldwide, and possibly for generations to come. The battles being waged in Egypt today go well beyond the ones making headlines.
Dr HA Hellyer is a Cairo-based commentator formerly at Gallup, Warwick University and the Brookings Institution
On Twitter: @hahellyer