Image source, ReutersImage caption, There will be family photos but little decision-making at Wednesday's summit

The European Union is like playing in the "Champions League", claimed one official in Brussels recently. Not, they said pointedly, a more minor domestic competition.

The message being that it isn't easy to win membership.

For years Western Balkans states have tried to climb the accession ladder into the EU.

But as their leaders arrive for a top-level EU summit in Slovenia, hopes may not be high for concrete progress.

There'll be family photos, lunch and all the usual pageantry when EU leaders meet their counterparts from Albania, Bosnia-Herzegovina, Serbia, Montenegro, the Republic of North Macedonia and Kosovo.

But it's not a decision summit on enlargement, rather a "reaffirmation" of ties.

Noises coming from the Commission can, sometimes, sound very positive.

EU Commission chief Ursula von der Leyen recently stood on a stage next to the Albanian Prime Minister, Edi Rama, and said, "Let me be very clear, Albania's future is in the European Union."

Albania, North Macedonia, Montenegro and Serbia all have "candidate status", although some nations are more advanced in the process than others. Bosnia is still a potential candidate, while Kosovo is not even recognised as a state by some EU members.

Countries are tested on their ability to align with a large body of rules and standards, divided into 35 chapters. It's never a simple process.

But these four candidates have formed a queue that now dates back to the early noughties.

One of the most recent stumbling blocks: a language dispute between EU member state Bulgaria and North Macedonia.

University of Oxford EU politics lecturer Eli Gateva says the accession process can be "held hostage to domestic politics".

Following previous rapid expansions, enlargement has in some cases, she says, become "another word for immigration – and this can be fuel for far-right parties".

Image source, EPAImage caption, Bridge to the future: The European Commission chief (C) opened a crossing between Croatia and Bosnia last week

France and the Netherlands are often named as among the most cautious EU member states when it comes to enlargement.

The EU is, after all, already wrestling with serious issues among existing member states, principally Poland and Hungary, on the all-important "rule of law".

So the case is made that the EU needs to sort out the structural issues within its own house before building on that extension.

Wednesday's summit statement is expected to go no further than "reconfirming" the bloc's commitment to enlargement, and even that took some haggling.

While the political process may appear painfully slow, money is fast being poured into the region with billions in grant funding.

Image source, ReutersImage caption, Relations between Serbia and Kosovo are tense and a two-week border row ended only days ago

Andi Hoxhaj, a scholar in EU Law at the University of Warwick, calls it an "economy first" approach. The idea being that if you integrate countries economically, the politics may follow.

Ursula von der Leyen already spent last week love-bombing the region, covering six countries in three days.

Following a phone call, the Commission chief and US President Joe Biden this week also expressed a statement of "strong support for continuing the accession process with countries in this region".

That is because the Western Balkans, which suffered so much in the bloody wars of the 1990s, are strategically important to the European Union.

"It's not our backyard, it's our front yard," one EU diplomat told me: and you want your front yard "clean and neat".

"If we are not going to be in the region, someone else will fill the void."

Eli Gateva agrees: "We have other foreign actors trying to vie for influence in this region such as China, Russia and Turkey."

Ask around and there can be huge reticence to name a date as to when the candidate countries might finally get an official seat around the EU table.

Slovenia, which holds the European Council presidency, reportedly (and unsuccessfully) urged the EU to commit to admitting the Western Balkan states by 2030.

The Slovenians believe there needs to be a strong political message to reassure the region that enlargement is still a priority; they see hopes of accession as a vital spur for candidate countries to tackle corruption and pursue judicial reforms.

While an EU official remarked this week that the door wasn't "closed", it certainly isn't gaping open either.

The danger is those countries in the waiting room start to look at other options, and the European Union's quest to project power fades away.