In an old black-and-white photograph, one wore long hair and a rakish moustache, the other thick-rimmed glasses.

Children of pedigree, they shared an undergraduate dorm at an American university. Forty years later, as political rivals at the height of the Greek crisis, George Papandreou – until recently prime minister – and Antonis Samaras symbolise the split personality of a nation with roots in left and right, chaos and greatness.

The sparring between the leaders of Greece’s two main political parties is over for now. But the forces they represent will clash in elections as early as February, shaping the next chapter of a society on Europe’s edge whose strife has an outsized impact on continental union, as well as the global economy.

The left-leaning Papandreou and the conservative Samaras are the yin and yang of modern Greece, heirs to historical divisions and symbols of interlocking currents of reform and tradition.

An acquaintance from their college days suggests that even amid public animosities, the two remain bound together by shared private history.

An old photograph of the two adversaries taken in 1973 in New Hampshire, hints at the forces that shape Greece even today, and the way that history and family shadow the individual efforts of those at the nation’s helm.

Papandreou sits with hands clasped, hair unruly. Samaras stands, clean-shaven, in a turtleneck sweater. Philip Tsiaras, now an artist based in New York City, and Stefanos Manouilidis, now an insurance broker, are also in the photo. No one smiles. The poses are formal, the lighting is studio-quality.

At the time, Greece was under military rule, and the elite united in opposition and exile, despite ideological differences that are playing out today. Tsiaras said Papandreou and Samaras were not “bosom buddies,” but they were thrown together in a tight-knit expatriate group. Papandreou, at home in the freewheeling spirit of the time, was “more American” and less politically ambitious than the straight-laced Samaras.

Yet Papandreou did not resist the dynastic pull. His grandfather had been prime minister; his father would become prime minister at the head of PASOK, a party with socialist roots. The young Papandreou’s rise was steady and seemingly inevitable. He held various Cabinet posts in the 1980s and 1990s, became leader of PASOK in 2004 and led the party to victory in general elections in 2009.

Samaras’ father, by contrast, was a heart surgeon. He did have relatives in politics, but none at the highest levels of government. His great-grandmother, writer Penelope Delta, killed herself when German troops entered Athens in World War II.

He later joined the conservative New Democracy party, which came to power after the junta’s fall. Early in the current crisis, Samaras took a nationalist stand, but his agreement to join a coalition government signalled support for the bailout path, or what might be called a ‘pro-Europe’ position.

That recent shift in direction reflects Samaras’ delicate efforts to cater to all constituencies while retaining the loyalties of his camp. It is a more nuanced approach than in the past. In the early 1990s, Samaras formed his own party, hastening the collapse of the government he once supported. But he spent many years on the political fringes and eventually returned to the New Democracy fold.

New Prime Minister Lucas Papademos, a former central banker and deputy head of the European Central Bank, is seen as departing from this partisan script.

Surveys indicate he is popular, but an early test comes on Thursday when Greek unions stage a 24-hour general strike to protest salary cuts and tax hikes required in exchange for international rescue loans.