European Union leaders are beginning a three-day summit at a seaside resort in northern Greece, where they are expected to debate the draft of a constitution for the bloc as well as their countries' ties with the United States and the situation in the Middle East.
More than 15,000 troops, police and Coast Guard personnel are patrolling the area around Porto Carras, a hotel complex near Salonika, Greece's second-biggest city. Greek officials consider the massive operation a test of their ability to mount credible security measures ahead of next year's Olympic Games in Athens.
It is not just the threat of terrorism that the Greeks are trying to cope with. They also face a flood of demonstrators protesting against capitalism, racism and the EU itself, which the activists accuse of being out of touch with its citizens.
In Salonika, which is expected to bear the brunt of the demonstrations, since the summit site has been closed off to protesters, merchants have boarded up storefronts in an attempt to prevent their shops from being damaged if violence breaks out.
Topping the leaders' agenda is the draft constitution hammered out by a convention chaired by former French President Valery Giscard d'Estaing. The document calls for scrapping the EU's revolving presidency, which gives every nation its turn in the spotlight for six months, and replacing it with a long-term president of the European Council as well as an EU foreign minister. And it says the EU's executive body, the European Commission, must be slimmed down.
The leaders of the 15 member nations and the ten that are expected to join next year will have a chance to express their thoughts on these issues even if formal negotiations on the text are not scheduled to begin until October. Experts like Steven Everts, at London's Center for European Reform, say hard bargaining lies ahead.
"When it comes to deciding the exact powers of the European Council president, when it comes to the exact terms under which the Commission president will be elected, and whether he or she will be able to sack individual commissioners or not, the real power battle is ahead," he said. "And I think that, in the weeks and months ahead, we are going to see some blood in the street on those questions."
The EU leaders are also expected to try to patch up relations with the United States in the wake of the Iraq war. And some, as analyst Steven Everts points out, are hoping the EU can play a role in helping to implement the Middle East peace plan known as the road map.
"One idea in that area that is bubbling around is the idea of a peacekeeping force to be sent to the West Bank and Gaza, the idea being that the road map says that Israel should withdraw from the occupied territories, but everybody's very concerned that a security vacuum might emerge," explained Mr. Everts.
Host nation Greece has been pushing Balkan countries to speed up economic and political reforms so that they can eventually join the EU. To that end, it has invited leaders of five Balkan countries to join their EU counterparts on Saturday to discuss the matter.