Hope for political stability in Egypt any time soon faded on Monday morning as news of the mass-killing of Muslim Brotherhood supporters outside the Republican Guard headquarters in eastern Cairo began filtering through.

No matter which narrative is more accurate — the army maintains that it was repelling an attempt by Brotherhood members to enter the base by force and release deposed president Mohamed Morsi, said to be inside, while the protesters claim to have been fired upon without provocation — the fact remains that at least 50 people were killed and hundreds wounded.

Meanwhile, for Hamas, the fall of the Brotherhood is a major blow. Under Mr Morsi, Egypt was not always helpful to Hamas — it destroyed more smuggling tunnels in the past year than during any previous period — but, on a diplomatic level, it acted as Hamas’s guarantor.

One of the worst outbreaks of violence since the Egyptian revolution began in January 2011 underlined the Egyptian army’s determination to control the country for the foreseeable future and that the Muslim Brotherhood, as the largest party, is not going to relinquish power easily.

While the Brotherhood does not have the capability to challenge the army on the streets, its large membership and millions of supporters will continue challenging the legitimacy of any government emerging following their overthrow. Having won the presidential and parliamentary polls, the Brotherhood will also make it extremely difficult to launch a new round of elections.

The bloodshed and increasingly heavy-handed policies of the army will also deter rival parties from joining a national unity government.

On Tuesday, the military-backed interim government led by Adly Mansour and defence minister, General Abdul Fatah al-Sisi, appointed economist Hazem el-Beblawi as prime minister, and the secular opposition leader Mohamed El Baradei as vice-president.

Mr Beblawi will lead a technocratic government which, significantly, looks unlikely to include Islamists.
While the generals and politicians struggle to put their country back on track, Egypt’s neighbours are having to tread carefully.

In Israel, even before the military takeover, Prime Minister Benjamin Netanyahu had instructed ministers and senior officials not to speak in public on the situation in Egypt, but the feeling of satisfaction was clear.

One senior security official said that “we have a good working relationship with the Egyptian army and our experience of Al-Sisi is certainly positive.” Behind the scenes, Israeli diplomats have been lobbying the US not to describe the ouster of Mr Morsi as a coup, which would jeopardise US military assistance to Egypt.

As in previous upheavals in Egypt, Sinai erupted with jihadists attacking police and government buildings.

The Israeli government allowed the Egyptian army to deploy more troops in the peninsula and, in what will be another blow to Hamas, the border crossing between Egypt and Gaza was closed indefinitely following Egyptian claims that jihadists were crossing over from Gaza into Sinai.