While European elites have been preparing for the Treaty of Rome's birthday, two non-members of the European Union have in recent weeks done little to contribute to a party mood.
By Kjetil Wiedswang
Commentator for Norway's Dagens Naeringsliv newspaper
Happy enough as we are: Norway's king (L) shakes his PM's hand
The Swiss have quarrelled with the EU over taxes - rejecting suggestions that theirs are too low - and Norwegian officials have got tough over plans to increase the country's fee for membership of the European Economic Area (EEA).
The fee is already more than 200m euros ($266m; £137m) annually and Norway has signalled its objection to the EU's proposals by delaying the start of negotiations.
Normally, however, the four main West European non-members of the EU are regarded as some of the less troublesome members of the European family. They do not get into rows at summits, and the three EEA members are better than most EU states at implementing EU legislation.
Norway even has some unexpected expertise to offer the EU.
Near Luxembourg Square in the Belgian capital is a Norwegian lobbying firm called The Brussels Office, run by an ex-Norwegian government official, Paal Frisvold. One of its specialities is helping Balkan bureaucrats prepare for membership negotiations with the EU. They have assisted the Croats, their latest clients are the Serbs.
Norway has applied for EU membership four times.
Twice in the 1960s (when France's Charles de Gaulle said "Non") and then in 1972 and 1994, when membership agreements were reached after lengthy negotiations - only to be turned down by the Norwegian people in referendums.
Cuckoo clocks and fish
This unique experience today has a market value in the less Eurosceptic parts of Europe.
FOUR EU OUTSIDERS
Main EU non-members: Iceland, Liechtenstein, Norway, Switzerland
Schengen pact members: Iceland, Norway
EEA members: Iceland, Liechtenstein, Norway
Schengen pact: No border controls on borders between Schengen member states, passport-free travel
EEA: Members of the European Economic Area pay a fee to participate in the EU's internal market
Each of the four main West European outsider nations has its special reasons for not participating in this week's party.
Switzerland is what was left over when the Europeans formed their nation states. Italian, French and German ultra-conservatives escaped to the mountains, joined forces and then created 500 years of peace, the cuckoo clock and the gnomes of Zurich.
Today the Swiss feel a bit disorientated, because the country's business model - neutrality - is problematic. Totally surrounded by the EU, they "have no-one to be neutral against".
They organise their relationship towards the EU via a series of bilateral agreements, and there are no signs that this will change in the foreseeable future although the Swiss have voted for joining some European initiatives, such as the Schengen area, where border controls have been lifted.
But as long as the economy thrives (and it does), the Swiss stay out, knowing that they are a geographically unavoidable reality in Europe.
Neighbouring Liechtenstein, another non-member, is a monarchy, and even more of a tax haven, while being effectively the 27th canton of Switzerland.
It is, however, a member of the European Economic Area, a special arrangement for the European Union fringe, allowing free access to the internal market. EEA members have an obligation to implement the bulk of EU law, but without any influence over it.
The second largest non-EU member of the EEA is Iceland, which has a single reason for not being a EU member - a deep fear of the EU Common Fisheries Policy. That fear is absolutely rational and Iceland's position is not going to change any time soon.
Better off outside?
As for Norway - according to the UN, the best place on Earth to live - its Europhobia is based on history, geography and luck.
Norway gained independence as late as 1905 (from Sweden) and the word "union" still has a bad political taste.
Being a vast country - the distance from the capital Oslo to the extreme north is about the same as from Oslo to Rome - it has developed strong local political cultures, and a deep-rooted unease about the idea of central rule.
It never developed a strong industrial base, unlike big brother Sweden, and shares the fishery culture with Iceland.
Add oil, discovered in the North Sea in the late 1960s, and the Norwegians got the means, as well as the will, to go it alone.
Opinion polls vary, but for some time now, a steady majority has been against joining, although the ruling Labour party, the opposition Conservatives and the business community are keen to join.
The ruling parties have not been able to convince a majority of Norwegians to join the EU because recent history has shown that Norway has done very well outside the union.
The threat of being isolated, which was used by the Yes-camps in both the 1972 and 1994 campaigns, has been proven unfounded.
The "EEA membership fee" is high, but Norway can afford it. There are regular debates about the silliness of having to implement laws that others have made - and as a northern, Protestant country, Norway implements them quicker than most.
The counter-argument is that with four million people in an EU of half a billion people, Norway's influence would be microscopic, anyway.
So for the time being the EU's 27 insiders and four Western outsiders seem reluctantly satisfied with the arrangement.
This may change one day, but probably not for some time yet.