Nostalgia is perhaps the defining sentiment in a disenchanted Arab world, punctuating conversations in Cairo, Egypt, and Beirut, Lebanon, as it does in Baghdad. It marks the fact that something -- a measure of tolerance, a more libertine life, the cosmopolitanism of a confident culture -- has been lost. Beirut had its downtown, before the civil war wrecked it, where families posed before the statue in Martyrs' Square. Now a preserve of the rich, it was once a crossroads of class, where cinemas abutted the fish market, and boutiques and banks shared space with vegetable vendors. Cairo had its downtown -- the Groppi cafe and cinemas such as Rivoli, Metro and Opera -- whose era ended with a fire in 1952 and a revolution that followed. Not all was wonderful, of course. Cairo was far more pleasurable if you were a foreign resident, sometimes never speaking Arabic, than an Egyptian. Sightseers in Beirut could ignore a ring of misery on its outskirts, populated by disenfranchised Shiites. But few would dispute that identity, be it sect, ethnicity, even class, was more malleably defined. And nearly everyone would agree that chauvinism had yet to best tolerance. 'How do you tell that story without seeming too nostalgic for a world that in many respects we wouldn't want to bring back?' asked Mark Mazower, author of 'Salonica, City of Ghosts.' 'That's the dilemma.' To Mazower, the nostalgia is not something singularly Arab, but rather a universal narrative that seems to capture failure as much as it does loss. 'Everybody is conscious of how difficult nation-states find it to establish stable and tolerant regimes,' he said. 'The nostalgia reflects the sense of their crisis today.' There is neither stability in postwar Baghdad, nor tolerance. But Maysoon al-Damluji stops short of blaming the American troops who have mostly left her capital. 'I have always said an army is an army, regardless. It's just young men with guns,' said Damluji, an architect and lawmaker from a prominent family. 'You don't expect an army to take care of a city. You don't expect an army to be sensitive to people's needs.' 