Marred by racial abuse, fraud and intimidation, the campaign for this weekend’s elections in Bosnia-Herzegovina has illuminated an alarming picture of rising instability across the entire Balkan region, where the reviving forces of ethnic nationalism, overtly and covertly backed by Russia, are locked in a contest for power and influence with pro-western, pro-EU parties.

Nearly a quarter of a century after it was signed, the complex Dayton peace accord that ended the Bosnian war shows signs of falling apart. Milorad Dodik, the separatist-minded leader of Republika Srpska (the Bosnian Serb region of Bosnia-Herzegovina), has waged a divisive campaign, stoking tensions with the country’s Bosniak (Bosnian Muslim) community.

Dodik’s tactics, replicated to a lesser degree by Croat and Bosniak politicians, have been crude and blatant, according to a report last week by Transparency International. The anti-corruption watchdog recorded an “unprecedented” level of campaign violations by all sides. “The abuses, conducted in the most open manner, [included] direct threats and attacks, pressure on voters and vote-buying,” it said.

In one instance, Dodik, who is standing for the Serb seat in Bosnia’s tripartite state presidency, admitted a one-off payment to pensioners was a sweetener to win votes. He also threatened to sack workers at a publicly owned company if they backed a campaign rival. On Thursday, the electoral commission fined him for hate speech.

But it is Dodik’s undisguised secessionist instincts, close links to Russia, and hostility to the EU that are fuelling fears of wider disintegration. He claimed last month that the US and Britain were interfering in the elections: “Forty British operatives came to Bosnia. Five are right now in Banja Luka ... Every day they are dealing with issues of destabilisation.” Altogether, Dodik said, foreign governments, meaning EU countries and the US, had spent €200m trying to influence the polls. Both the UK and US deny meddling.His claims were backed by Aleksandar Vučić, Serbia’s president. When the elections were over, Vučić promised, he would present “astonishing evidence of the most brutal interference of certain western powers in RS [Republika Srpska]”.

Analysts detect Russia’s hand behind such allegations, pointing to Dodik’s latest, pre-election meeting with Vladimir Putin and Moscow’s close economic and energy ties to RS. It has been clear for some time that Russia’s overall effort to subvert and thwart western democracies, dramatised again by last week’s spy scandal in the Netherlands, extends to the western Balkans. But its level of involvement there is growing.

“Russia makes little secret of the fact that it will do what it takes to ensure the Orthodox Christian countries of former Yugoslavia do not join Nato,” wrote Ivor Roberts, former UK ambassador to Belgrade. It opposes countries seeking EU membership, too. According to Macedonia’s prime minister and US officials, Moscow manipulated last weekend’s referendum in which an allegedly Russian-financed nationalist boycott derailed Skopje’s hopes of joining the EU and Nato. Russia flatly denies these and similar claims relating to a failed coup in Montenegro in 2016.

The EU has completely abandoned the idea of substantive constitutional and political reform in Bosnia Jasmin Mujanovic, political scientist

Bosnia’s elections have highlighted fears that Dayton’s other creation, the Bosniak-Croat federation, whose electoral law is in dispute, could also split apart. Dragan Čović, leader of the main Croat political party and a member of the state presidency, complains Croats have been marginalised and is agitating for a Croat-majority sub-state. Čović has support from Croatia’s nationalist government and recently met Dodik, further intensifying speculation about secessionist moves. Bosnia’s struggling economy – despite decades of EU assistance it remains one of Europe’s poorest countries – its endemic corruption, organised crime and media freedom problems, youth unemployment of around 50% and consequent “brain drain” are all factors feeding resurgent ethnic tensions and hardline nationalist rhetoric.

So, too, is the widely shared perception that Bosnia has been forsaken by an EU that has cooled to further enlargement and is more concerned with its own migration and nationalist-populist tensions. The flipside of aggressive Russian influence-peddling is European complacency, bordering on neglect. To complicate matters further, Recep Tayyip Erdoğan, Turkey’s anti-EU, pro-Russia president, is championing Bosnia’s Muslims.

“The international community, and in particular the EU, has completely abandoned the idea of substantive constitutional and political reform in Bosnia. And that’s played directly into the hands of malign, entrenched and reactionary political figures,” a political scientist, Jasmin Mujanovic, told Euronews.

The Sofia summit last May and a later meeting in London between the EU and six aspiring Balkan countries– Serbia, Montenegro, Macedonia, Albania, Kosovo and Bosnia – undoubtedly caused great disappointment. Their so-called “European perspective” on a timetable for future membership was eclipsed almost indefinitely, due to opposition led by France.

Nor can Bosnia and other struggling democracies look again to the US for salvation. Donald Trump’s admiration for Putin, compounded by “America First” indifference, is adding to security fears across the western Balkans. Trump recently made brutally clear that he would fight no battles for Montenegro, and he is no fan of Nato or the EU. Meanwhile, two former Trump campaign aides have become paid lobbyists for Dodik.

Is Europe prepared for another Balkan meltdown? It seems not. Is one brewing? It could be. After Dayton, Nato forces in the region numbered 54,000 troops. The EU-led military mission in Bosnia is now down to a mere 600. Like UN peacekeepers in 1995, they could find themselves hopelessly outgunned.