In an ideal world, the Eurovision Song Contest would be all about music and cross-border camaraderie. In reality, delicate diplomacy is essential to prevent politics from spilling into the annual glitz fest.

A cast of hopeful artists from 26 countries will compete in this year’s final on Saturday in Sweden, homeland of inventor Alfred Nobel, who gave his name to the famous international peace prize.

This year’s motley crew drags with it to Stockholm a good handful of conflicts — some historic and some more recent — between countries like Russia and Ukraine, Azerbaijan and Armenia, Serbia and Albania, and so on.

The European Broadcasting Union, which organises the contest, “will never successfully depoliticise Eurovision,” Jess Carniel, social scientist at the Australian University of Southern Queensland and a Eurovision specialist, explained to AFP.

What it can do, however, is try to avoid bum notes that would dampen the mood in a show that pulls in a global TV audience of around 200 million.

Last year Armenia was asked to modify the lyrics of its song “Don’t Deny”, as it pointed too directly at Turkey’s refusal to describe the massacre of Armenians a century earlier as “genocide”.

In 2014, the votes cast in Crimea were counted as Ukrainian, ignoring the fact Russia had annexed the region. “Technical reasons,” Eurovision explained.

For the 2012 edition held in Baku, human rights activists lashed out at the sums Azerbaijan had spent to polish the image of its authoritarian regime. Eurovision officials steered well clear of the debates around detained protesters or tensions with Iran.

The list goes on and this year’s show in Stockholm is no exception.

Eurovision’s loyal army of gay fans may be more welcome in Stockholm than they were in Baku, but controversies have flared about the politically-charged lyrics of Ukraine’s song — and about flags.

Fury erupted when the flags of Palestine, Kosovo and Spain’s Basque region all appeared alongside the black banner of the Islamic State on a list of banned flags sent out to people buying tickets for the event.

Though Eurovision was not responsible for the blunder, it quickly apologised and relaxed its rule which normally permits only the flags of UN members, the European Union and the rainbow banner that represents the LGBT movement.

This year Eurovision has also authorised the use of the Sami minority’s flag to endorse Norwegian performer Agnete, who has roots in the community, and the Welsh flag for Britain’s Joe Woolford.

– Alliances between nations –

Eurovision’s most sensitive rule leaves some room for interpretation: “No lyrics, speeches, gestures of a political or similar nature shall be permitted.”

But the organisers have given the go-ahead to Ukraine’s entry “1944”, which recalls Soviet dictator Joseph Stalin’s deportations of Crimean Tatars towards the end of World War II.

“When strangers are coming, they come to your house, they kill you all, and say, ‘we’re not guilty, not guilty’,” the song begins.

Russia fiercely opposed the song, saying it brought up old history in order to denigrate Russia for the annexation of Crimea in 2014.

But Eurovision officials ruled that “the title and lyrics of the song do not contain political speech” and it could be performed in the competition.

Their approach was quite different in Moscow in 2009, just a year after the conflict between Russia and Georgia.

The Georgian group Stephane & 3G were told they had to rewrite their title “We Don’t Wanna Put In”, a thinly-veiled swiped at Russian President Vladimir Putin. Georgia preferred not to participate instead of giving in.

Eurovision expert Carniel said the most troubling songs for the organisers “are the ones that arguably have double meaning (…) or those that overtly refer to contemporary issues.”

There have also long been grumbles about tactical voting, and several statisticians have scientifically shown that geopolitics play a role in the results.

Both the French and Britons like to blame their flopped performances on continental alliances, claiming that the Nordics vote for the Nordics, the Slavs for the Slavs and the former Soviet republics for their kin.

Catherine Baker, a historian at Britain’s University of Hull, said in a research article that the accumulation of victories for former Soviet states in the 2000s irritated Western Europeans to such a degree that the scoring system was changed in 2009.

Eurovision added professional juries’ votes to those of television viewers, to try to weed out some of the tactical and emotive voting.