Anybody watching Turkish TV over the last month could be forgiven for thinking that Mohamed Mursi was Turkish. News channels that broadcast wildlife documentaries during the recent Turkish protests aired long and impassioned debates about what was going on just across the Mediterranean. For pro-government commentators, it was a game of “compare the coup”—exactly which Turkish military intervention did the Egyptian one resemble the most? Was it 1960? 1971? 1980? 1997? (The foreign minister reckons it was 1997.) Anybody risking a more nuanced view faced accusations of groveling at the feet of tyranny.

Government circles in Turkey clearly fear that what has happened in Egypt could happen to them. too. More radical Turkish secularists doubtless hope it will. In reality, though, the parallels between the two countries are tenuous. The Justice and Development Party always was one of a kind, for all the talk in the Western press about it being a democratic model for the region. So, as it falls, is Mursi’s Muslim Brotherhood. It isn’t just that coups are almost unthinkable in Turkey today, or that Turkey’s economy continues to grow while Egypt sinks further into insolvency. It is, above all, that Recep Tayyip Erdoğan has charisma and guile and Mursi has little of either.

Yet there is one crucial thing, other than a shared ideological heritage, that links the two men: the structural similarities of the political groups that they lead. Like the Muslim Brotherhood, Mr. Erdoğan’s political base owes its strength to its tightly-knit and hierarchical grassroots network. In opposition, that made it immensely resilient: it regrouped quickly after being swept from power by the military in 1997. Between 2003 and 2008, it linked shields and fought off military and judicial efforts to shunt it aside again.

But the same characteristics that gave it strength in the past have left it ill-suited to rule in a consensual way since it took full power. Mr. Erdoğan’s political charisma has always depended heavily on his having enemies. Enemies have enabled him to justify the extraordinary hold that he has over his party apparatus. First it was the Kemalist establishment. Then, with the army defeated, it was Israel. Now that he stands at the zenith of his power, it is the world, and half of his own people. Listening to him speak since the street protests kicked off late in May has been like listening to Saint-Just, the philosopher of the Jacobin Terror: “Since the people has manifested its will, everything opposed to it is outside the sovereign, and all that is outside the sovereign is the enemy.”

“I won more than half the vote, therefore I am the nation.” The domestic implications of this vision of perfect social homogeneity are obvious—society stops being a society and becomes a barracks. In Mr. Erdoğan’s case, though, there are also signs that it has rubbed off on his vision of the wider world too, fatally weakening his pretentions to regional leadership.

In the early years of his time in power, one of the guiding principles of his foreign minister’s foreign policy was “zero problems with neighbors.” In some ways, it is arguable whether the slogan differed that much from the most famous statement of Turkish foreign policy there is, Kemal Atatürk’s “peace at home and peace in the world”. (Both, when you think about it, are the sort of cautious stance you would expect the leaders of new and as yet unconsolidated regimes to strike.) But it seemed to tally with the government’s move away from Turkey’s traditionally conservative approach to the wider region towards a more proactive approach, and again it went down well in the West.

Gradually, though, and in parallel to Mr. Erdoğan’s rise to absolute power inside Turkey, his government’s claim to be a pragmatic big brother to the region, a broker between Israel and Palestine, willing even to push for peace with Armenia, morphed into something more ideological. Ankara weakened its admittedly limited leverage over Palestine through its strong support for Hamas. It fell out with Iraq over its support of Tariq Al-Hashemi. It may now be supporting radical Salafi groups against the Kurds in Syria. And it fumed over the fall of the Muslim Brotherhood while Riyadh and other regional capitals publicly gloated.

Mr. Erdoğan’s mistake has been to fall victim to his own intoxicating domestic rhetoric about being the voice of the people, the soul of Anatolia, the long-awaited champion of pure Turkish and Islamic values, and to assume that he speaks for a perfectly homogeneous mass of people. He doesn’t. His support base is not homogeneous. Turkey certainly isn’t. As for the wider Sunni Arab world, it couldn’t be more disparate.

Islamist politicians like Mr. Erdoğan are more powerful today than they have ever been. Paranoia and a barracks-room mentality served them well during their years in opposition. If the region is to escape from a vicious circle of coup and counter-coup, of secular authoritarianism followed by Islamic authoritarianism, though, they need now to replace it with something more nuanced.

The counterpoint to this piece can be read here.