By Ivana Sekularac and Matt Robinson
BELGRADE (Reuters) - An ailing Serbian nationalist, released before a verdict in his lengthy war crimes trial in The Hague, returned home on Wednesday vowing revenge on former friends and "traitors" who seek integration with the West.
Vojislav Seselj, whom doctors say is suffering from cancer of the colon which has spread to his liver, was given a raucous welcome by hundreds of supporters who packed Belgrade airport.
Seselj's almost 12-year detention, drawn out by the defendant's repeated obstruction of his trial and the replacement of one of the judges, had become an embarrassment for the tribunal, which ordered his release on Friday citing "compelling humanitarian reasons".
The 60-year-old's return has put Serbia's government in an awkward spot.
Seselj was political mentor and close friend of Serbia's current president and prime minister, Tomislav Nikolic and Aleksandar Vucic, before both men broke from his Radical Party in 2008 and swung behind efforts to join the European Union.
Nikolic and Vucic took power in 2012 and have sought to distance themselves from Seselj, a hardline proponent of the nationalism that fueled wars in Bosnia, Croatia and Kosovo during the breakup of Yugoslavia in which more than 120,000 people died.
Addressing supporters from the balcony of his party headquarters, Seselj said he would topple the government, branding Nikolic and Vucic "renegades and Serbian traitors who renounced their honor and renounced Serbian nationalism to become the servants of foreign powers".
He denounced the Hague tribunal as a "wounded globalist beast" out to destroy the Serb nation.
With the defection of Nikolic and Vucic, Seselj's Radical Party - for years the biggest in Serbia - lost its place in parliament. But Seselj holds almost cult-status among some hardliners in Serbia, who say they will rally in central Belgrade on Saturday to show their support for him.
Seselj handed himself in to The Hague in 2003, charged with recruiting, financing and inciting followers to commit murder, ethnic cleansing and other war crimes in Bosnia and Croatia during the rule of late Serbian strongman Slobodan Milosevic.
With his release, a verdict in the trial may never come.
"It is sad and discouraging that the tribunal did not manage to complete the process after all these years," said Croatian President Ivo Josipovic, an expert on international law. "Seselj is an example of the inefficiency of international justice".
(Additional reporting by Zoran Radosavljevic in Zagreb; Writing by Matt Robinson; Editing by Crispian Balmer)