Although European leaders did not set any new hurdles to membership in the European Union, the general tone of this week's summit meeting in Brussels suggests that the enforcement of entry criteria for future EU hopefuls will likely be enforced more toughly than in the past.

The European Union is already set to expand to 27 members on Jan. 1, when Bulgaria and Romania will be officially welcomed into the club. Turkey is an official candidate and the western Balkan states -- Albania, Bosnia, Croatia, Macedonia, Montenegro and Serbia -- could soon be added to that list.

European Commission President José Manuel Barroso said on Thursday that all 25 leaders "support the decision unanimously" to stall accession talks with Turkey for as long as the government of Prime Minister Recep Tayyip Erdogan refuses to open its sea and air ports to the southern Republic of Cyprus, an EU member since 2004. A Monday draft of the summit conclusions did not specify how many chapters of the membership talks should be suspended, leaving that decision to the discretion of the EU ministers.

Summit leaders could not agree on a way forward for the stalled EU constitution, which was put on ice by French and Dutch voters in May and June 2005. While a Monday draft of the summit conclusions says "the tempo of enlargement must take into account the ability of the Union to admit new members," the British delegation is diametrically opposed to this maxim, having "always rejected the notion that there has to be an automatic link between enlargement and institutional change," British Foreign Secretary Margaret Beckett said on Friday.

Other points of contention included references to dropping national vetoes on police and judicial cooperation, which were struck from the draft conclusion at the behest of Britain, Poland and the Czech Republic. German Chancellor Angela Merkel is set to take over the rotating EU Presidency from Finland in January, and said she would focus her efforts on reviving the EU constitution.

For the business daily Financial Times Deutschland, the German EU Presidency will be a test of Merkel's leadership:

"In order to inspire the citizens, it is not enough to confine oneself to platitudes. If Merkel wants a successful EU Presidency, she will have to be fairly vague for the time being -- for in the Europe of the 27, presidential backroom-diplomacy is the best way to make progress with the EU constitution."

"Granted, the constitutional treaty is neither a popular nor an easily comprehensible project for the citizens of the EU; but without the institutional reforms it entails, the EU would become paralyzed in its actions after 2009. Merkel therefore has no other option but a gradual approach to save large parts of the constitutional treaty."

"The process is not to be finalized during the German Presidency -- but it will be known whether there can be a new foundation for the EU by 2009. Merkel's foreign policy strength will be measured by it."

The business daily Handelsblatt writes:

"No wonder all eyes are on Merkel. The chancellor is expected to straighten things out and lend Europe new momentum. The only question is, Where is this élan supposed to come from? For one, Merkel's hands are tied by her grand coalition government (a power-sharing agreement between the conservative Christian Democrats and the left-leaning Social Democrats); she cannot act nearly as freely as Helmut Kohl once could. Furthermore, the chancellor steps on the brakes herself on many important issues."

"Merkel is also on the defensive with a view toward EU enlargement. Not much is left of her proposal to use a revision clause to set Turkey a kind of ultimatum. The German parliament didn't even mention it yesterday. That should hardly be any different during the summit in Brussels. There is apparently a lack of courage to fight."

For its part, the center-left daily Süddeutsche Zeitung argues that the EU needs a constitution before any new members are admitted into the EU:

"The individual states have too much power to blackmail. (…) The Union cannot incorporate one more single country until it has given itself a new constitution -- politically and financially. That goes for the western Balkan states, and especially for Turkey. For this cumbersome candidate at the latest, the Union needs rules that go beyond the present constitutional blueprint (which leaves the states much sovereignty). Because this requires a lot of energy and will take years, Angela Merkel is right: Some aspirants should be offered a cooperation that does not, for the time being, lead to accession."

"Such a strategy would direct attention to the core question: How much enlargement can the European Union bear? The new perspective is indispensable if Europe wants to keep its character as a political force that is strong enough to face the problems that overwhelm the nation-state in a globalized world -- be it terrorism, impoverished refugees, energy supply or climate change. The EU will only find common solutions to these problems if it ratifies efficient decision-making processes and remains affordable for taxpayers."

"A boundless enlargement, on the other hand, degrades the Union to a free-trade zone without political unity. This would be the British-American model: The EU encompasses as many states as possible, without integrating them -- a deliberate recipe for weakness. The time has come for Germany and France to promote a new direction."