On the morning I left Cairo, my street corner was obscured under several metres of rubbish, a dozen filthy stray cats fighting over the scraps. Local news was reporting on the city's low-level anarchy and the opportunistic criminals exploiting its security vacuum. As my taxi grumbled along another gridlocked highway, I couldn't help but feel relieved to be leaving for a few days.

Istanbul delivered a bizarre kind of culture shock: a functional - and highly visible - state. On the elegant boulevard in Beyoglu, the city's achingly hip shopping and nightlife district, fluoro-suited sanitation workers swoop on litter like nervous housewives. Even the stray dogs have their ears tagged, and the city's legion of cats are largely well-fed and confident.

Officially, Istanbul counts around 13 million souls - but the true figure is much higher. The young night manager at our hotel, Muhurram, who is studying EU law, says when census time rolls around, Turks who've moved to Istanbul go back to their hometowns to be counted, in part because the federal government pays the local governments by the head. "Unofficially, it's closer to 16 or 17 million," says Muhurram"

There's no sign of austerity on Istanbul's European shore. The city isn't just prospering - it's practically jumping out of its skin. Ten years after a financial collapse had Istanbulites paying millions in unstable lira for a cup of coffee, the economy is accelerating at breakneck speed - in the first quarter of 2011, Turkey's economy grew by 11 percent, outpacing even China. According to a 2010 Forbes list, Istanbul now has the fourth-highest number of billionaires, one rank behind London. Elias, a graphic designer, told me he'd lived for years in the United States, but that he was staying put in Istanbul now. "There's just so much money here," he exclaimed. One only has to take a Saturday night stroll in the city's middle-class districts to see what he's talking about - the restaurants are packed and many of its bars are still jumping at sunrise.

But beneath this outrageous prosperity, a deeper, darker mood pervades Istanbulites - a stark contrast to the loud, joyous irreverence of 'light-blooded' Egyptians. Istanbul native and author Orhan Pamuk calls this feeling hüzün, or melancholy - a pervasive sense of 'poverty, defeat and the feeling of loss', and a yearning to be Western. Pamuk says Istanbulites have a poetic attachment to this collective identity, but as Turkey reasserts itself as a world power, this hüzün is gradually shedding some of its defining factors.

Photo by Jess Hill.

Another elegant stray in Istanbul.

Turkey's former obsession with the European Union is a case in point. Just a few years ago, Turkey was scratching at the EU's door. Now, local newspaper headlines crow about a 'post-EU world', Turkey no longer sees itself as a country whose historic vocation is to join Europe," says one commentator, who characterises Turkey as having a 'European overlay' covering a 'very Turkish identity'.

Barely an article gets written about Istanbul without a bridge-between-East-and-West reference. But not all Istanbulites see it this way. "We have not been a bridge - we have been a one way street, looking only towards the West," says Nesrin Uçarlar, a Turkish academic I meet one afternoon. That was the vision of Turkey's founding father, Kemal Ataturk, 'the great moderniser'. When the militant secularist expelled the last Islamic Sultan, he banned the key identifying features that linked Turkey to the Islamic world: he replaced the Turko-Arabic script with the Latin alphabet, banned the fez and the hijab, and even went as far as banning the muezzins from making the call to prayer in Arabic (translation is forbidden in Islam, so Ataturk's decree was tantamount to banning it altogether).

Since Recep Tayyip Erdogan became prime minister in 2003, however, this obsession with the West has begun to shift eastwards again. "Only now are we beginning to see the role we can play in the East," says Uçarlar, "and how we can identify with that." For now at least, religion is still a relatively private affair for many Istanbulites (decades of autocratic secularism has made sure of that). Here is another stark contrast with Egypt. On the faces of older men in Cairo, piety is a competition for 'prayer calluses' - ugly burn-like marks on the forehead that result from repeatedly pressing their forehead on a prayer mat. The larger the callus, the greater the piety (some younger Egyptians are said to rub sugarcane on their foreheads to achieve the same effect). In Istanbul, outward displays of religion are uncommon. I haven't seen any men kneeling in the street at prayer time, and in many parts of town, few women wear the headscarf (let alone the rarely-sighted niqab).

This quiet approach to Islam is not true of greater Turkey, of course. For several years, secular businessmen have complained of government discrimination, claiming that prime contracts and tax breaks are doled out to people who publicly espouse the Islamic beliefs of the ruling AK (Justice and Development) Party.

Photo by Jess Hill.

Living with relics of empire.

And here's the question that refuses to go away: is it just a matter of time before Turkey slides back into authoritarianism, this time in an Islamic guise? It's not hard to find canaries in that coalmine. Turkey now leads the world in the number of journalists it has in jail, and academics are being suspended, arrested and even imprisoned on the basis of researching 'controversial' issues, like 'the Kurdish question' and the Armenian genocide. During five days in Istanbul, I twice saw hundreds of riot police gathering nearby Taksim Square, a popular spot for demonstrations. When Istanbul's Kurdish population tried to get together to celebrate Newroz (Kurdish New Year) on Sunday, riot police responded with water cannons and tear gas. And in February, Prime Minister Erdogan gave the secularists another reason to worry, declaring that his AK party wanted to 'raise a religious youth'.

The Turkish Prime Minister insists that Islam and democracy can go hand-in-hand. Newly elected Islamist parties in Egypt and Tunisia hold up Erdogan's Turkey as the ideal of a thriving Islamic democracy, as does the West. But how many other thriving democracies jail their intellectuals?

There's a strong sense, especially among Istanbul's intellectual class, that while Erdogan has reformed and progressed Turkey in ways few thought possible a decade ago, he still needs to be watched like a hawk. Whether their concern will end up translating into a broad organised resistance is hard to say. Right now, Istanbul's economic and cultural boomtime is eclipsing most other cities in Europe and the Middle East. For many Istanbulites, that might be enough.