In the space of two months, Greece got a new prime minister and a new leader of the main opposition party. Both men are the products of the best Greek and US education, having studied at Athens College and then at Amherst College in Massachusetts, where they were even roommates. They are relatively young (57 and 58) and slipped easily into politics, where, from early on, each was expected to have a brilliant career. Prime Minister George Papandreou and New Democracy leader Antonis Samaras both speak foreign languages, read international newspapers and are as comfortable in the world as they are at home in their local constituencies. They may be political rivals but the two men also - literally and figuratively - speak the same language. Both are ambitious and want to leave their mark on Greece. With the problems Greece is facing, we could say that the ascent of these two politicians is the best thing that the country could expect. But their stories so far are no guarantee that they will meet the challenges of the time. Costas Karamanlis had all of Papandreou and Samaras's privileges, opportunities and talents and yet managed to do so little with them during the five-and-a-half years he was prime minister and the 12 years that he ran New Democracy. Karamanlis has a PhD from the Fletcher School of Law and Diplomacy at Tufts University and, at 53, is, in fact, younger than the other two. Karamanlis, though, did not have the stomach to take on the forces of apathy, corruption and bad habits that have made Greece so unproductive and so unjust to its citizens. After last December's disaster, when the government's instinctive inertia allowed rioters to take over Athens for days on end after a policeman shot and killed a teenager, and with the economy coming to the brink of collapse, voters decided that they had had enough. First they threw Karamanlis and his government out of office, electing George Papandreou and his PASOK party after rejecting them in two consecutive elections, and then, last Sunday, they picked Samaras over former Foreign Minister Dora Bakoyannis. New Democracy's voters made their anger clear: Nearly 800,000 showed up to vote, sticking to their guns even when technical problems at voting stations forced them to spend hours waiting to cast their ballot. Samaras, who was recently welcomed back to the party from which he had defected before bringing down the ND government in 1993, was a marginal figure in Karamanlis's administration, holding the lowly post of culture minister. Bakoyannis was the most senior figure after Karamanlis and had stood by his choices even when she disagreed with them. This, more than anything, must have cost her the election. Despite their common qualities and experiences, and perhaps because of their superb but different political pedigrees, Papandreou and Samaras are very different politicians. The prime minister appears to have his eye on the future far more than on the present. He wants to impose a new, open form of government on the Greeks as if the country had the egalitarian traditions of Scandinavia. It seems to be taking him some time to confront the reality of Greece's problems. Samaras, who cultivates an image of being both populist and patrician, has pledged to renew New Democracy's right-wing credentials and will almost certainly take a tough stand on foreign policy issues. Playing the ideological and patriot cards may be a useful way of strengthening his party's identity and marshaling the troops but it is also likely to tempt Samaras into pandering to the public rather than supporting the effort to revive the economy and reform society. Papandreou and Samaras have the talents to make a difference. With the huge mandates both have in their respective roles, it is now up to them to show whether they have the grit to confront Greece's problems, the vision to lead the country forward and the courage to cooperate.